Jake 'n a Box

Jake wasn't just waiting around for valet yesterday.
He was also working it out. Back to doing martial arts training there is a bit of a mystery about it, and it's not the hoodie of invisibility that he is trying to work.
Let's go to the pictures.

Why does it look like he's trying to avoid being notice going in?We see Jake going into work out with a big brown box.
But where did it go when he left? Is it a Dojo and Post-To-Go?

Also it looks like it was a private class, as we see the instructor, unlocking the gates after class.Interesting that it's not just the doors are locked, but the gate was pulled and locked so no one can get even close to the door while Jake was in there.

But it wasn't just Jake and the instructor in there.
See the white sleeve of a t-shirt here.
And then they're out of the picture, while Jake and the instructor are still at the gate.And why does he bring in that big gym bag and yet he doesn't change his clothes at all. What's in there?
Someone knew that Jake goes to work out there, because they are in a position to get the picture going in and they also stay to take pictures of him leaving. The question is why? What were they wanting to catch on film?