It was just weird. Carla walking by, her and Peter looking at each other and not saying a word to each other before he leaves. What did you think?

Has carla descended to streetwalking now? She seems to spend an awful lot of time walking up and down the street bumping into people. We should be grateful she didn't turn round and go back the way she arrived.

Haha it was a blink-and-you-miss-it moment

It's Peter and Carla though. They don't need to say a word, they only have to look at each other and I believe that was the writer's way of conveying that there are still feelings there.