After watching it a couple of times, what scares me more than that is that behaviour, the jumping around is exactly what my younger dane, Sasha does, when she's getting ready to "wrassle" with the pups - she plays rough and they do too, I'd just be worried that that dog's "playing" would be a little too rough for that baby. Then she gets the zoomies and she has darn near knocked me over a time or two and I am built like a brick craphouse.
Don't get me wrong - having two danes, I know what gentle giants they are, but I would be afraid to put them in a compromising position like that.... Maybe I worry too much.