New Behaviour for me

I've been watching the interactions between our 3 rescues and our 2 new ones very closely.  Most of it is pretty normal and obvious but something transpired a short time ago that has me a little stumped.

Scotty, a now very tubby Scottish Fold rescue, was sleeping in a cat bed near the downstairs window.  Julius, our new DLH rescue, came down from his hiding spot and stopped at the bed.  Did the usual "sneaky sniff" and then sat there staring at him for a moment.  That's when the weirdness started.  His tail began to wag back and forth with great vigor, he'd slowly extend his paw out with claws extended, then retracted his paw.  Scotty woke up but remained laying down stomach exposed to Julius and very lazily put his paw up in a half batting motion which Julius sniffed and began "talking" to Scotty.  This repeated a couple times, Julius remaining seated for the duration, then contact was actually made and Scotty jumped back into a defensive posture.  Julius sat there for a second then hopped up on the ledge and lay down.  Scotty remained frozen for a bit then retreated.

I can't figure out if this was Julius attempting to invite Scotty to play, a dominance thing, or an attempt to push Scotty out of the area so he could have the space to himself.  It was a lot of mixed signals from both but very interesting to observe.

Ideas?

It's hard to tell without actually being there, but it sounds to me like Julius wanted to play but was a little hesitant about it.   If it had initially been a dominance thing, Scotty would have recognized that right away and not have left his tummy exposed.  With the shock of actual contact, Scotty rejected Julius's overture and took off.  Julius then took over the space to show his own dominance.  

Anyway, that's my wild guess.   Cat behavior is fascinating!   

That makes sense.. and given that Scotty is a bit of a whipping boy he isn't used to friendly play so probably interpreted it as an attack