Steps to replicate the issue (include links if applicable):

• Open any image description page on Commons
• See resolutions of thumbnails that are suggested for download below the main image
• See what they are linked to

What happens?:
In most cases the resolutions are different. Eg. for this image:
commons.wikimedia.org/wiki/File:ПАК_у_мису_Хроні1.jpg
"320 × 213 pixels" is linked to a 330px thumbnail
...
"2,560 × 1,707 pixels" is linked to a 3840px thumbnail

What should have happened instead?:
The declared and actual resolutions should be consistent. Current situation is misleading for users.

Software version (on Special:Version page; skip for WMF-hosted wikis like Wikipedia):

Other information (browser name/version, screenshots, etc.):