The poster of the original clip added the source in the commentsBeing one to never trust what a clip on twitter seems to be showing... aside from it being someone seeing pictures of themselves from decades ago, if you watch until the end you see even the lawyer is showing some amusement and AFAICT this is before any of the the questioning started, not some random interlude in the middle?
Don't get me wrong, I understand the point and if he deserves to be strung up then string him up but inappropriate humour immediately prior to something serious is surely a fairly normal human response to the situation? In the sense of not being something I would read anything more into.