Good Morning,
I display problem with firefox avatar, avatar visualize very large profile of 160x160 px.
The problem on firefox not on chrome as attaching images.
(Translated by google)

Hi Christian,

if you view source at that page, around line 82 you can see this CSS

img {
  box-sizing: border-box !important;
  height: auto !important;
  max-width: 100% !important;
}

img {
  box-sizing: border-box !important;
  height: auto !important;
  max-width: none !important;
}