A "reasonable" person might have to be shown the relevant features, but then would recognize them thereafter. The clip actually opens with helpful labeling, so that's taken care of.
After that, the motions themselves become obvious -- right down to that little lip-smacking thing that babies do when they stop crying. "Reasonable" people, among whom I count myself, can easily recognize the baby in the picture, and can see that she is, in fact, making the motions of crying.
What you're apparently saying, though, is that a "reasonable" person would never see those things, even after being shown what to look for. IOW, those people are not "reasonable" at all, but willfully ignorant.
Sorry, you must have misunderstood what I was saying. I wasn't saying that a reasonable person can only be defined as someone who doesn't see the child in the video.
A reasonable person could also draw the conclusion that the child in the video is just moving about.