Post Featured Image: Placeholder can't be smaller than 48px width and height

[iamtakashi]

Description

The placeholder for the featured image cannot be smaller than 48px in width and height. It should allow it to be smaller than that.

I was working on a theme with small featured images. I wanted it to be a square of 42px, but there seemed to be CSS that specifies the minimum height and width in the editor. This causes a discrepancy between the actual featured image and the placeholder.

Step-by-step reproduction instructions

1. Go to the editor
2. Place a query loop block with a featured image
3. Change the size of the featured image to, say, 42px square.
4. The placeholder stays 48px square.

Screenshots, screen recording, code snippet

Environment info

WP 6.4.1
Gutenberg Trunk
Chrome Mac

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes