On the wiki, in Incident 239-b
a humorous video clip is mentioned.
Addendum: To the anonymous employee who took the Site-17 surveillance camera footage of Drs. Clef and Kondraki having a swordfight, set it to the "Highlander" theme song, and posted it to the company intraweb with the title, "There Can Be Only One": We will find out who you are, and when we do, you'll be missed greatly.
P.S. Whose smart idea was it to allow SCP-076 view the footage?
I think for a possible easter egg, you could have a low quality version of this clip play somewhere in the game.