Bug: Preview image in composer are not shown in a meaningful way

[ivanminutillo]

When adding several images to a post and the describing them, the images might be cropped in a way that makes it impossible to understand what description should fit to what image if they are too similar. The example below is about a user interface detail in two different states. The important differences are not visible on the crop.

In general, preview images should not be cropped but scaled down, and users should have a chance to look at a bigger-size version of these previews to verify these are the actual images they intended to share. Reference: https://playground.bonfire.cafe/post/01G8R1DNJGBFY791PCWSNZW766#