I was going to go with, in the beginning, simply Lex and Talia being in various places around the facility, nothing too incriminating seeing as Lex owns it. But as it goes on, I was hoping to have someone show up (hooded figure perhaps?) who seems like they might be a little shady and it could be interpenetrated that they are with the league of assassins (perhaps some sort of emblem will be seen in a reflection in the video, or something spoken despite there being no audio, is recognised?) I hadn't quite worked it out in full but that was my initial thought. 

If there's anything you'd like to add, or you'd like to 'play' the video in your post, certainly feel free!