Board Thread:Speculation House/@comment-26025032-20160110222427/@comment-4010415-20160110232637

The video they showed on the screen cut out the part where Mercury stood up and walked over to her after she had walked away, in order to save time and get right to the point of showing us and Yang that what Yang saw wasn't real.

To be honest, there seems to be a bit of inconsistency there just from the animators making a bit of a mistake when animating. For all we know, multiple different animators worked on multiple things in that part.