First of all we already have topic thumbnails you can enable it from the ACP.
If that isn't enough you can take a look at the code that makes it work and duplicate that.
I'm having an issue with my current forum where this happens when someone clicks on a notification and it shows the topic that was created:
Any clue on how to fix this problem? It seems like it's a kerning issue.
forum url: http://community.3dprintingclub.net
Can you double-check the icons associated with those forums? Do they have no icon set?
Ah yes, that is correct! I've not selected an icon since i wanted to do custom images with icons not present in the font awesome collection.
The icons in the font awesome collection are not an option so how can i have this fixed?