I've watched a few videos, but there is no way to really assess a player by half a dozen shots. Your getting highlights, so they're going to show the kid at his best. You can see some speed, power, change of direction, footwork, etc., but its very limited.
To truely look at what you've got you need whole game films, probably several of them. Then you look for things like how consistent is this guy? Does he string great plays together? Does he take plays off? Does he make plays when the game is on the line? Is he durable? Is he a leader? Does he makes his teammates better?
When you look at those you have no idea what kind of competition the kid is playing as well. He may look really fast or strong based on who he is playing.
Not saying there is no merit to them, and they are enjoyable to watch, but those folks projecting what a kid will be based on a dozen plays are silly at best.
