[TheLastSuperman]

Check the plugin or setting for the plugin that is adding in the custom avatar, per a post above the url looks to be doubled so whats going on is (imo) - the plugin is injecting the site url as well before its avatarfilename.jpg filename snippet; like a path prefix of sorts, the issue is the site url was already being called (assumably by default) so check the plugin and/or have you made any recent url type changes to any settings/.htaccess (trying rewrites of any sort etc) and think back what was recently done that made the avatars change after that?

Something is making the actual siteurl called twice in a row... what are your settings in:
AdminCP > Settings > Options > Site Name / URL / Contact Details

For base path and the component urls?

Edit: Aye and although its like a bathing suit bottom, next time please grey out or crop the screenshot not to show ads of that nature... luckily this time like I said it resembles a bathing suit bottom and its summer but not all ads are that "friendly" in regards to moral compass and viewer discretion being advised and what not (lol).