Okay, so imagine you have a broom that you use to clean your house with. But sometimes, when you use the broom a lot, the bristles (the part that sweeps the floor) can get all messy and tangled up. So you want to straighten them out again.
That's where a shaker broom vise comes in. It's like a special tool that helps you hold onto the broom while you fix the bristles. It's called a "shaker" because it helps you shake the broom to get the bristles back in order.
The vise part of the tool is like a clamp that you put the broom handle into. It holds onto the broom so it doesn't move around while you work on it.
So basically, a shaker broom vise is a tool that helps you fix your broom when the bristles get all tangled up. It holds onto the broom while you fix it, so it's easier and faster to get it looking nice and new again.