I remember watching it sometime ago ...
If I remember correctly, I found it as "Ronda Rousey foot tickle". So, the person that originally posted it thought that. I think it seems like a ticklish reaction. But, unfortunately, as we can't see her feet, we won't be able to confirm it ...
Does anyone know where this video came from? Because maybe it was from a show or something. Knowing the context, it'll be easier to know if she was ticklish ...
It's always nice to remember that, as FFT32 said, Ronda Rousey admitted being deathly ticklish more than once. She was really blunt when describing her ticklishness. So, it's not a nonsense to think that's a ticklish reaction. It's really plausible in my opinion ...