From the video poster: "Foal in Germany learning about a halter. It eventually gave up and layed down."
There are different ways to train foals to halter that may be easier on them and avoid this type of strain on their heads, necks, and bodies. Clicker training is a no-stress method of halter training, as well as approach / retreat.
We don't want to give the horse neck problems, rip any muscles, tendons, or ligaments, which may last his lifetime.