What is this?

[Chippy_Tea]

What is this?

Yes i know its a bar

 

[Agentgonzo]

Are you talking about the big brass hoop?

The bar has a section in it that is currently down. When the bar keep wants to come out from the behind the bar to the rest of the pub, they raise this section of the bar and it rests on the brass part safely (the raised section of bar rests in the vertical position)

 

[Agentgonzo]

In this famous scene, the section of bar flips up the other way and rests against the wall, instead of the brass section

 

[Chippy_Tea]

This is a better view and shows the foot rail also ends there -

"divider" or "service divider". It serves to keep standing customers to one side, away from the part of the bar where servers pick up drinks - Also notice the opening under the bar, the bartender (in some designs) can lift the top and gets in and out. You don't want customers standing there blocking access.