It would be most helpful t

It would be most helpful to know your software. But a good clue (I have never done this) is to look at the background images, watch the trees. It appears to be a single shot, clipped the few seconds he wanted to use then placed then on a time line and used a crossfade (?) trans, if he used the crossfade he would have had to cut the time of the crossfade down to the minimum. But that is what it looks like.