Maybe not a bug, but an improvement opportunity.
I ran into the same issue with the responsive curve mod on 2.0.11 and just noticed that 2.1 has the same issue. In responsive mode (smaller screens) images are taken out of proportion due to the current index.css settings (see attached examples) .
.bbc_img, .atc_img {
border: 0;
max-width: 100%;
}
With this the original image (attachment 1) is squashed on small screens (attachment 2)
Should be extended to:
.bbc_img, .atc_img {
border: 0;
max-width: 100%;
height: auto;
}
This way the images keep their original aspect ratio at all times... (attachment 3)
Applied sorry kinda forget this: https://github.com/SimpleMachines/SMF2.1/pull/3417/commits/de4f42241552743a913983be9e570a74b9aa5b92