Kit Harington picked 8x06 for his episode, so that is what he is being judged on and where the clip has to come from.
I think they should have shown the part where he and Dany were talking before he killed her. The only problem is that Emilia Clarke was the better actor. We are supposed to feel sorry for Jon for making that decision, which no one is but that’s probably what they were going with. (And to be honest Emilia was the better actor in her death scene…)