Image numbering labels not passed to model when referencing multiple images

Description

When users attach multiple images across a conversation, the Claude Code UI displays sequential image numbers (e.g., [Image #5], [Image #6]). However, this numbering metadata is not passed to the model, causing confusion when users reference specific images by their displayed number.

Steps to Reproduce

1. Start a conversation in Claude Code
2. Attach several images across multiple messages (e.g., 6 images total)
3. The UI shows them labeled as [Image #1] through [Image #6]
4. Ask Claude about a specific image using the displayed number, e.g., "What is in [Image #6]?"

Expected Behavior

Claude should understand which image [Image #6] refers to and respond about that specific image.

Actual Behavior

Claude does not receive the image numbering metadata and cannot map the reference to the correct image. It only sees the raw images without their assigned numbers.

Impact

• Users naturally use the numbering system displayed in the UI to reference images
• This creates a confusing experience where the UI suggests a referencing system that doesn't actually work
• Users have to resort to describing images by content or position instead

Suggested Solutions

1. Pass the image number metadata to the model so it can understand references like [Image #6]
2. Or, include the image label in the image's alt text or context when sending to the model
3. Or, document this limitation and suggest alternative ways to reference images

Environment

• Claude Code CLI
• Issue discovered in multi-image conversation workflow