I've noticed the more comfortable they get with it the easier jumping gets, but it can take time for them to be fully confident that what they are jumping on isn't going to go flying and that they know how to put their feet.
Getting mine amped up helps too, when they're really going for the toy or food and I ask for an up on something they are more likely to fling themselves at it.
And, there is the fact that she's not exactly a short dog
So things my dogs jump onto because it's easier than stepping onto are things that are just easier for her to step onto. I think once she's more confident and you can find things that are that right inbetween height (like a table! Because I do like encouraging people to have their dogs all jump on tables so that everyone can have bad mannered dogs like mine!) of not too tall and not too short it will come. But you can tell from the video's she's still figuring out why this stupid human is having her do this weird thing.