This is shear speculation on my part, based on my experience in the archaic F-4 and F-111 airplanes:
They are probably demonstrating a "tactical departure", in which the two airplanes make hard turns away from each other just after takeoff so as to immediately get into a tactical formation, which involves around a mile of separation.
Well, it was a mile in the F-4 anyway, I don't know what they use in the Ego Jet. Ten miles maybe since it's based on keeping as far apart as the wingman can have good visual on the lead.
The wingman there is just "shining his a**" a bit, note the leader is not in such a steep bank. They are both climbing so he's not gong to hit the grass, he just wants to be in on the show.
Jim