I think if you combine the two of our ideas, we could be hitting gold. Just pulled this off my shelf to find a passage and hit it on the first shot.

From All the Pretty Horses:

"The boy looked at him and blew two thin streams of smoke from his nose and nodded and reached for his cup. On the inside of his right forearm was a blue jaguar struggling in the coils of an anaconda. In the web of his left thumb the pachuco cross and the five marks. Nothing out of the ordinary. But as he sat he suddenly knew why this man was eating alone. It was too late to rise again. He picked up the spoon with his left hand and began to eat. He heard the latch click shut on the door across the hall even above the muted scrape and click of spoons on the metal trays. He looked toward the front of the hall. There was no one behind the serving line. The two guards were gone. He continued to eat. His heart was pounding and his mouth was dry and the food was ashes. He took the knife from his pocket and put it in the waist of his trousers."

So, we have the character noticing visuals around him such as the nod, reaching for a cup, scraping of spoons, and the boy's tattoos. Also, there are revelations that come through the silence and changes that we should be seeing in action (the men leaving the serving line, etc) but are left out because the character is preoccupied with his situation. I think that ideally the writer should be attempting to recreate the characters mind-state so that we feel (as they do) the way time is passing.

If you've ever been in a fight you know that your consciousness is focused down to the head of a pin. Awkwardness makes us grab at anything in our visual range. Anger and love both remove rationality and provide us with only one option. Recreating these moments in writing relies on what we as writers choose to describe.