Show preview images in st.file_uploader

[jrieke]

Checklist

• I have searched the existing issues for similar feature requests.
• I added a descriptive title and summary to this issue.

Summary

When uploading an image in st.file_uploader, it shows a generic file icon for the uploaded image, see below. We could show a little preview of the image instead.

Why?

Just a nice little UX improvement :)

How?

Whenever the uploaded file is an image, replace the file icon in the file uploader with a preview image. We could also do the same thing for documents, e.g., if you upload a PDF, show a preview of the first page.

Additional Context

No response

[github-actions]

To help Streamlit prioritize this feature, react with a 👍 (thumbs up emoji) to the initial post.

Your vote helps us identify which enhancements matter most to our users.