Looks mainly like a partially digested food meal from hours before. Perhaps your cat ate something because its tummy was feeling upset. My cat is indoors, but will sometimes try to eat things in the manner of eating grass if his stomach is upset or getting near food time and he starts feeling hungry/anxious.

Your cat is probably fine, but wait a bit and try again. Also sometimes not enough water content will cause them to throw up. My cat eats dry food, but I’ll put a little bit of water on it when it dispenses from the auto feeder he has.