diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index f9ca79449..39aaadcf0 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -14,6 +14,7 @@
 
 ### Fixed
 
+- Images in steering and follow-up messages, including `prompt()` while streaming, are now resized like images in idle prompts instead of being sent and saved at full size ([#11738](https://github.com/earendil-works/pi/issues/11738))
 - A failed token refresh of an MCP connection no longer registers an OAuth client or replaces the PKCE verifier of a sign-in in progress, which made that sign-in fail. MCP sign-in now refreshes the stored tokens with the stored client even when the loopback callback port changed, instead of registering a new client and opening the browser. Ctrl+C in `/mcp` and the `--timeout` of `pi mcp login` now also stop a sign-in while it waits up to 25 seconds for another pi process's token refresh, and a refresh lock that fails for another reason than that wait now fails the sign-in instead of opening the browser.
 - Fixed RPC mode ignoring an extension's `ctx.shutdown()` while idle, for example from a timer: the process kept running until the client sent another command. pi now shuts down right away when idle, and a shutdown requested by an extension command waits until the command's `prompt` response is written ([#11599](https://github.com/earendil-works/pi/issues/11599))
 - Fixed changelog notes repeating on every fresh launch when the installed package version has a prerelease suffix, such as `0.1.5-20261020.7`: the saved version was read as `0.1.0`, so the `0.1.1` to `0.1.5` notes counted as new each time. A saved version without `major.minor.patch` now shows no notes and is replaced by the installed version, instead of showing the whole changelog ([#11703](https://github.com/earendil-works/pi/issues/11703))
diff --git a/packages/coding-agent/src/core/agent-session.ts b/packages/coding-agent/src/core/agent-session.ts
index dbe36c365..5d341c4d7 100644
--- a/packages/coding-agent/src/core/agent-session.ts
+++ b/packages/coding-agent/src/core/agent-session.ts
@@ -43,6 +43,7 @@ import type {
 	TextContent,
 	ToolResultMessage,
 	Usage,
+	UserMessage,
 } from "@earendil-works/pi-ai/compat";
 import {
 	clampThinkingLevel,
@@ -408,6 +409,8 @@ export class AgentSession {
 	private _steeringMessages: string[] = [];
 	/** Tracks pending follow-up messages for UI display. Removed when delivered. */
 	private _followUpMessages: string[] = [];
+	/** Queued user messages whose images are normalized when they are delivered. */
+	private _queuedMessagesWithImages = new WeakSet<AgentMessage>();
 	/** Messages queued to be included with the next user prompt as context ("asides"). */
 	private _pendingNextTurnMessages: CustomMessage[] = [];
 	/** Context-only custom messages queued during a run, flushed once the current turn's tool results are in. */
@@ -1153,6 +1156,12 @@ export class AgentSession {
 					}
 				}
 			}
+			// Normalize queued images at delivery, before events and persistence see the message,
+			// so they get the same resize as idle prompts with the current model's limits (#11738).
+			if (this._queuedMessagesWithImages.has(event.message)) {
+				this._queuedMessagesWithImages.delete(event.message);
+				await this._normalizeQueuedMessageImages(event.message);
+			}
 		}
 
 		// Emit to extensions first, then notify public listeners.
@@ -2327,11 +2336,9 @@ export class AgentSession {
 		if (images) {
 			content.push(...images);
 		}
-		this.agent.steer({
-			role: "user",
-			content,
-			timestamp: Date.now(),
-		});
+		const message: AgentMessage = { role: "user", content, timestamp: Date.now() };
+		if (images?.length) this._queuedMessagesWithImages.add(message);
+		this.agent.steer(message);
 	}
 
 	/**
@@ -2344,7 +2351,24 @@ export class AgentSession {
 		if (images) {
 			content.push(...images);
 		}
-		this.agent.followUp({ role: "user", content, timestamp: Date.now() });
+		const message: AgentMessage = { role: "user", content, timestamp: Date.now() };
+		if (images?.length) this._queuedMessagesWithImages.add(message);
+		this.agent.followUp(message);
+	}
+
+	/** Replace a queued user message's images in place with normalized ones, appending hints to its text. */
+	private async _normalizeQueuedMessageImages(message: UserMessage): Promise<void> {
+		if (typeof message.content === "string") return;
+		const [first, ...rest] = message.content;
+		if (first?.type !== "text") return;
+		const images = rest.filter((block): block is ImageContent => block.type === "image");
+		const normalized = await this._normalizePromptImages(images);
+		const text = normalized.hints.length > 0 ? `${first.text}\n\n${normalized.hints.join("\n")}` : first.text;
+		message.content = [
+			{ type: "text", text },
+			...rest.filter((block) => block.type !== "image"),
+			...normalized.images,
+		];
 	}
 
 	/**
diff --git a/packages/coding-agent/test/agent-session-queued-images.test.ts b/packages/coding-agent/test/agent-session-queued-images.test.ts
new file mode 100644
index 000000000..800445bf3
--- /dev/null
+++ b/packages/coding-agent/test/agent-session-queued-images.test.ts
@@ -0,0 +1,94 @@
+import { deflateSync } from "node:zlib";
+import type { ImageContent, TextContent } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import { createHarness, type Harness } from "./test-harness.ts";
+
+function crc32(data: Buffer): number {
+	let crc = 0xffffffff;
+	for (const byte of data) {
+		crc ^= byte;
+		for (let i = 0; i < 8; i++) crc = (crc >>> 1) ^ (0xedb88320 & -(crc & 1));
+	}
+	return (crc ^ 0xffffffff) >>> 0;
+}
+
+function pngChunk(type: string, data: Buffer): Buffer {
+	const length = Buffer.alloc(4);
+	length.writeUInt32BE(data.length);
+	const body = Buffer.concat([Buffer.from(type, "ascii"), data]);
+	const crc = Buffer.alloc(4);
+	crc.writeUInt32BE(crc32(body));
+	return Buffer.concat([length, body, crc]);
+}
+
+/** A solid gray RGB PNG of the given size, base64 encoded. */
+function createPng(width: number, height: number): string {
+	const header = Buffer.alloc(13);
+	header.writeUInt32BE(width, 0);
+	header.writeUInt32BE(height, 4);
+	header[8] = 8;
+	header[9] = 2;
+	const row = Buffer.alloc(1 + width * 3, 0x80);
+	row[0] = 0;
+	const raw = Buffer.concat(Array.from({ length: height }, () => row));
+	return Buffer.concat([
+		Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a]),
+		pngChunk("IHDR", header),
+		pngChunk("IDAT", deflateSync(raw)),
+		pngChunk("IEND", Buffer.alloc(0)),
+	]).toString("base64");
+}
+
+function persistedUserContent(harness: Harness, text: string): (TextContent | ImageContent)[] {
+	for (const entry of harness.sessionManager.getEntries()) {
+		if (entry.type !== "message" || entry.message.role !== "user") continue;
+		const content = entry.message.content;
+		if (typeof content === "string") continue;
+		if (content[0]?.type === "text" && content[0].text.split("\n")[0] === text) return content;
+	}
+	throw new Error(`No user message "${text}"`);
+}
+
+async function waitFor(condition: () => boolean): Promise<void> {
+	for (let i = 0; i < 200 && !condition(); i++) await new Promise((resolve) => setTimeout(resolve, 25));
+}
+
+describe("AgentSession queued message images", () => {
+	let harness: Harness | undefined;
+
+	afterEach(() => {
+		harness?.cleanup();
+		harness = undefined;
+	});
+
+	// Regression test for #11738: queued messages skipped the image resize idle prompts get.
+	it("resizes images in steering, follow-up, and streaming prompt messages", async () => {
+		harness = await createHarness({ responses: [{ text: "first", delayMs: 300 }, "second", "third", "fourth"] });
+		const image: ImageContent = { type: "image", data: createPng(1200, 9000), mimeType: "image/png" };
+
+		const run = harness.session.prompt("idle");
+		await waitFor(() => harness!.session.isStreaming);
+		await harness.session.steer("steer", [image]);
+		await harness.session.followUp("follow up", [image]);
+		await harness.session.prompt("streaming prompt", { images: [image], streamingBehavior: "followUp" });
+		await run;
+		await waitFor(() => !harness!.session.isStreaming && harness!.faux.callCount >= 4);
+
+		for (const text of ["steer", "follow up", "streaming prompt"]) {
+			const content = persistedUserContent(harness, text);
+			const images = content.filter((block): block is ImageContent => block.type === "image");
+			expect(images).toHaveLength(1);
+			expect(images[0].data).not.toBe(image.data);
+			expect((content[0] as TextContent).text).toContain("original 1200x9000, displayed at 267x2000");
+		}
+		const sentImages = harness.faux.contexts
+			.flatMap((context) => context.messages)
+			.flatMap((message): readonly { type: string }[] =>
+				typeof message.content === "string" ? [] : message.content,
+			)
+			.filter((block): block is ImageContent => block.type === "image");
+		expect(sentImages.length).toBeGreaterThan(0);
+		expect(sentImages.some((block) => block.data === image.data)).toBe(false);
+		expect(harness.session.pendingMessageCount).toBe(0);
+	});
+});