I love this! In the first moment I thought; this guy looks slow, ponderous, clumsy even, and look how he leans over his partner. & then they start dancing! What a delight. It's not a particularly complex dance, pretty much a repeated figure, but the easy, relaxed musicality of it, and the energy, is so enjoyable. & to me it's got heart. There's a whole army of bright young dancers who'd score far more in superfluous elegance and variety – without a trace of that warmth and affection that's so typical of the milongas.
Something I see here that I've not noticed so much in other videos is torque, how precise he is in using the energy of turning.
I don't know what to call these videos from Cachirulo. They aren't demonstrations, they aren't 'performances' either. Just two people having a great time dancing together. & the shouting from the guys: there's a lot of teasing going on. But Javier just grins, he's having a ball. & so, I guess, is Isabella.
There's one other video with this couple on the Cachirulo channel. We've got to thank Cachirulo again and again for the hundreds of videos on his channel. It's such a great cross section of that amazing milonga, Cachirulo, of tango at the start of the 21st century.