Wow, an 80? I just checked again and I got a 40/100. So I do know we need a cache plugin and we have been re-optimizing pictures a lot (and I know we have more since this new site being built be three people, one of which did not optimize anything when uploading.)
The report is showing it's trying to load the following images:
and those should only exist in the Rev slider that sits on the home page, not on this posts page. If you look at the HTML there is Rev slider code there and I'm not sure why? Is there a chance that XTheme's category post pages load up a widget and then hides it?