what does ''the granularity of each minute becoming more apparent'' mean?
3. Richard’s hands flexed, then relaxed. What could he do, snatch the cigarette away? His headache was worse. The pill was wearing off, the granularity of each minute becoming more apparent. He wanted to check his phone. His son kept smoking, his exhale threading thinly through the air before breaking apart.
(Northeast Regional By Emma Cline)

Question

what does ''the granularity of each minute becoming more apparent'' mean?
3.	Richard’s hands flexed, then relaxed. What could he do, snatch the cigarette away? His headache was worse. The pill was wearing off, the granularity of each minute becoming more apparent. He wanted to check his phone. His son kept smoking, his exhale threading thinly through the air before breaking apart.
(Northeast Regional By Emma Cline)

Answer

I think that it is describing the time dilation that can sometimes happen. You sometimes see that in movies, where they slow the clock down, and you see and hear the second hand on a clock ticking over very slowly. Here, it is using the same idea for minutes. Each minute seemed to become a whole chunk of time.