Inspecting the CSS, you seem to have this set for unread icons:
If it is set to this (presumably in the SPs):
Then the icons show.
BTW it's really worth getting to grips with the browser console as this will generally tell you what the issue is. This is how I found the problem just by inspecting an icon that appeared with one that didn't.
You should also look at resizing those icons as they are too big, which is why they are the size they are and cropped.