Okay, so my thoughts on this aren't fully formulated, but watching the "crazy fan" video I was struck by Mark saying he didn't think Sophie knew who he was. Taken on its face it obviously means that Sophie was so self-absorbed and image obsessed that Mark found it surprising that she would remember her nerdy, unassuming class mate. However, in light of the new video it seems clear that Mark was in some way involved with Sophie's creation/brain washing/whatever is actually going on. Which makes me wonder, what if Mark is seems so wary because Sophie isn't supposed to know he exists PERIOD. Maybe seeing the glitches of Lara in the former episode somehow triggered memories of the early days of her existence. What if the crazy fan video is the beginning of Sophie becoming aware that she is an ai/being brainwashed/etc and what we're seeing in the following episode is her trying to disguise her new awareness, and ultimately being punished and eliminated for it?

The fact that Sophie went to Lara's house against her managers wishes also points to the possibility of her developing a free will. It seems that, if Sophie was a programmable AI, she should not have the ability to contradict her handler (which seems to be Chloe's role, at least in part).

The only thing that really makes me unsure of this theory is, if Sophie isn't supposed to know of Mark's existence, then why did he agree to go on her show?