fourth wall

US /ˌfɔːrθ ˈwɔːl/
UK /ˌfɔːrθ ˈwɔːl/
"fourth wall" picture
1.

an imaginary wall that separates the audience from the events on stage or screen

:
The actor broke the fourth wall by directly addressing the audience.
Breaking the fourth wall can create a unique connection with the audience.