This is with google chrome. I didn't see it in Firefox, but I haven't gone to check either. Not sure what it is, but its some image that isn't loading right and is interfering slightly with the posts. I've seen it occur under a number of posters. Not sure if its only moderators.
The reason is simple: the url used to load the icon (online, offline, busy, etc) is no longer valid: http://mystatus.skype.com/smallicon/{skype-name-here}
Also I should add that the reason it only happens in chrome is that it doesn't see the image as 404, thus doesn't show the alt message instead.