Question about mixing tenses

So, I'm currentlich reading Kobo Abe's "Kangaroo Notebook" and I'm a bit confused about his use of tense shifts.

In this scene in the picture, he starts with "I stepped" then "I noticed" but then he proceeds in present tense "It looks", "He doesn't", "He's", and in the end he switches back to past tense "the boy was having", "he wasn't", etc.

So, I'm wondering what's the function of this. This all happens at the same time, so it's no backflash.

Could it be that the present tense sentences are internal thoughts at the moment, while the past sentences are descriptions?