https://www.scienceofpeople.com/body-language-examples/

 Displaying similar body language to other participants during a social situation.

What it Means: Mirroring is a highly rapport-building cue that signals a desire to connect with someone else. People tend to mirror only whom they like, and seeing someone else mirror our own body language creates a feeling of similarity and likeness.

The Science: Mirroring is powerful. Studies have shown that mirroring leads to the following:

• Greater compliance² with requests. So mirror if you want to persuade someone.
• Higher sales numbers³. So be sure to mirror if you are in sales.
• Positive evaluations. So mirror your manager to build rapport.
• Even larger tips⁴ from customers!

Mirroring others is literally hardwired into our brains. Professor Joseph Heinrich⁵ from the University of Michigan explains that mirroring others helps us cooperate—which leads to more food, better health, and economic growth for communities.

How to Use it: Make sure to mirror subtly. If someone nods their head vigorously in agreement, and you do the same, you may come off as too obvious—this can lead to suspicion or decreased rapport.

You can also avoid mirroring someone entirely if you're disinterested in them or want to create boundaries.

If the other person is displaying negative body language cues, try displaying open positive language cues yourself to get them to open up, instead of copying their closed gestures.