Cool videos, but just because you can doesn't mean you should!

At least an elephant, having a trunk, can pull down a whole branch and make the effort worthwhile as that first video shows. It seems that a sauropod with only its tiny mouth for grabbing wouldn't be able to do that, so the outcome would be more like in that last video where the elephant was only able to grab a couple of leaves, which I assume can't have been a calorific win!