Gulfjoinery, did you try adapting this customization to 2.x yet:
Hello, is it possible to configure XenForo Media Gallery in a way to the keep the aspect ratio of pictures in Thumbnails? Not to cut something off, but to to fill it with white space? Thank you in advance! Kind regards, Frank
xenforo.com
This worked well for the 1.x branch.
Hoping others have adapted this to 2.1 as I'll need this option before I can upgrade to the 2.x branch.