As Pop is proposing the con on the widow to Nick and Al, the same couple (a blonde and a man in a vertically striped robe) walks past the window along the beach from right to left twice.
The amount of foam and beer in Pop's mug changes as Doc tries to get information on Nick from him at the dive bar.
After Nick ties his tie, he and Al walk into another room. A shadow of the boom microphone can briefly be seen on the wall to the left of the doorway.