Hello 
Thanks for bringing this up! I’ve made an update on topic image (thumbnail) section. 
With this update I replace background with <img> and optionally a backdrop image can be added to this. The backdrop can handle the small image (which not cover this section) empty area. It works like a hacky dominant color background with the default settings.
I have added some new settings. With this setting you can choose the:
-
Topic image section height (default: 300px)
-
Image fit
- cover (default)
- contain
- scale-down
- none
-
Backdrop image (default: disable)
-
Backdrop image blur
-
Backdrop image brightness
This is how it looks:
Default (image fit cover, no backdrop)
Image fit contain
Image fit contain with backdrop
Difference between image fit (cover, contain, scale-down and none)
small image
larger image
Difference between blur and brightness values
blur
50px, 25px, 10px
brightness
0.65, 0.55, 0.45
Edit: Forget to add the image fit none option.