stick a sock in it

[Egyption Arrow]

In the name of the Merciful Allah,
Hi, here is a part of a conversation I heard in some series:
- You know, if the editorial photos didn't sell the clothes, then it defeats the purpose. Now we have to try the arty way, Sharon said.
- Oh, blah blah blah, stick a sock in it, Phillis said.
I ask about the meaning of " stick a sock in it", and what does " sock" here refer to? Thanks ahead.

[Anglika]

"stick/put a sock in it" = shut up, be quiet. See: Put a sock in it

A sock is just that - the garment you you put on your foot.

[Egyption Arrow]

Is this vulgarity?

[Anglika]

It's not polite. It's something I would expect from a child.