In this isekai scenario, a person from our world ends up trapped into an anime.

Let's say he wakes up into a japanese highschool teen room. If he's from the West, he would notice the difference in furniture and in any case that he's not home. But that doesn't mean he's into an anime. Even if weird things begins to happen, he stll could not tell. Even if he sees characters from some famous anime, does he perceive things as anime?

I mean, what does he see? Does he see a drawn world? With how much details? What about perspective? What does he feel? How's the air? How do things feel when touched? How do they taste? What happens when he pees?

I mean, how does a person tell the difference from real world vs anime world via his senses?