Some pictures from external sites or hosts are sometimes victims of anamorphosis (vertical stretching) when posted in the 'issues' category. The problem is confirmed with Google Chrome as a web browser. I did'nt test with IE, Firefox or Opera.
Example of an affected picture here. The same picture (same host, same adress) is perfectly fine when posted in the 'comments' section, as you can see here.
The problem can happen randomly for several pictures in the same reported issue, as you can see it here.