Ghostery affects websites differently in Safari than in Chrome?

Edit Subject

In Safari on a Mac running Yosemite, when Ghostery is set to block all trackers, most (but not all) of the thumbnail photos on the home pages of Gawker websites - lifehacker.com, gizmodo.com, etc. - are just gray squares. When I click through to the articles, the photos render normally. When I look at the site homepage in Chrome, running Ghostery with all blockers tracked, the thumbnails show normally.

After testing each of the 14 trackers Ghostery found on Gizmodo's homepage, it turns out that in Safari 8.0, at least, it is the Twitter button, of all things, that somehow determines whether or not the thumbnail photos and GIFs appear. Stop blocking the Twitter button, and everything shows up. In Chrome, however, the photos appear regardless of this setting.

Is anyone else seeing this? Is this the only example? And why in the same of sanity would the Twitter button have anything to do with these pictures?