It's more like P.E.
Spanish class is more like P.E. class than math class. It's in your body more than in your head.
In P.E. class, you have to run the laps, you have to lift the weights, you have to play the game. Those are metaphors of course. (Except for playing the game. That one is quite literal, because during storyasking students are expected to guess the right answer. I say "guess" because only I know the "correct" answer. This is the game of TPRS®.)
As for the metaphors, running laps and lifting weights, they allude to students' responsibility to respond with movement to my words and physically perform in class. Example: I say "Clase, ¡imagínate! (Class, Imagine!)" and they look up and touch their thumb and forefinger to their chin. I am training them to put the sounds into their bodies and their bodies into the sounds. If they can't show me, consistently and promptly, that they understand, by doing the actions, they can't pass my class. Because they don't demostrate comprehension.
If students are putting their bodies into it, consistently and promptly, they are demostrating positive interpersonal communication. They are having fun (hopefully). They are more effectively acquiring L2. They are doing foreign language.