Lightbox does not work!

Hello Community, I enabled the lightbox feature. In the media tab the lightbox looks perfect, but when I click the media in the activity stream, the lightbox just looks horrible… I don’t know why, but maybe because of my theme (Enigma Premium). Does anybody from you guys know how to fix that?

Here is the link to my activity stream where you can click the media:

Thank you! Regards, TheSpecialKick