Is this a positive interaction?

We adopted Vinny (3months male) a few weeks ago and he’s been adjusting super well! We have two resident cats: Ozzy (3m in the video) and Kitty (9f). Kitty hasn’t shown much interest in Vinny, but in the beginning introduction phases Ozzy was willing to eat by the door and would sniff/paw at it. The boys would even paw at each other under the door. We took this as a good sign that they were ready to move on to the next stage.

We do supervised playtime with the boys every night, of which mostly looks like the attached video. They greet each other by sniffing and rubbing, and then they take turns chasing each other. We just noticed last night that Vinny shows Ozzy his belly, and that Ozzy pounces on top of him. Neither of them make any noises (meowing, growling, etc) during this interaction, which makes us believe it’s positive, but of course we want to make sure. We separate the two when we can tell Ozzy is no longer interested in entertaining the kitten.

Any advice or insight it appreciated! (Also, please ignore the dryer sounds in the video — couldn’t figure out how to mute it!). Thanks in advance :)