What is the significance of the narrator's daydream about the bulldog in Invisible Man

I think the crowd scares him like the bulldog once did as a child,he didn't trust the crowd.

"There was
a child standing in rompers outside a chicken-wire fence, looking in upon a
huge black-and-white dog, log-chained to an apple tree. It was Master, the
bulldog; and I was the child who was afraid to touch him."