Fight or play?

Hi! I recently got a second cat (5 days ago), 2 years female, neutered, to accompany my 4 years neutered male.

They got along pretty well - not best mates, but no ugly fights, they can stay at the same room, eat from the same bowl and use the same toilet.

However, they do this, especially when I’m around (see video). I never had two cats before, so a bit unsure whether it’s fight or play?

Appreciate any response 💓

PS. Male is the bigger one.