I have two cats, one of them, Sammy, is always affectionate. The other, Ginger, is very aloof. When I do yoga though, Ginger is even more affectionate than Sammy.
It’s cute, I will be in down dog and they will both rub against my legs or attempt to press their noses to mine. They have also been know to climb on my back and lie down, purring away, when I am in seated forward fold or extended child’s pose. They chirp at me too and neither of them are really vocal. They love rolling around on the floor beside me and rubbing against me. I have a “fitness room” that they’re only allowed in with me when I’m doing yoga (for their safety). As soon as they hear the door for that room open, they come running every time! Afterwards they are all over me, following me about or lying on me if I am seated.
I have always assumed that they feel the energy that yoga produces and it is pleasant to them.