When the milkman drops the milk every bottle shatters. When he walks away you can see three bottles on their side intact. When Blanche walks toward them they are shattered. When she leans down you see three milk bottles and one cream fully intact standing upright with spilled milk on the steps.
Milkmen made their rounds in predawn darkness, typically between 2 and 5 a.m. so that milk would be delivered for breakfast. They never delivered in broad daylight.
The phone number on the side of the milk truck is all digits. At the time phone numbers had two letter prefixes, I.e. MAdison, LEhigh, etc.
The "5th Man" racist group was referenced as a Biblical parallel to the Day Man was created - Genesis tells us that Man was created on the 6th Day (see Genesis 1: 24-31).