This is where an actor is called back to do the lines again, usually because something went wrong with the sound recording on-set. Also known as "automated dialog replacement" (ADR).
The fun part? Now the actor gets to do the line with the intended emotions while lip-synching themselves.
This is much more common than you may think. As a rule of thumb, any time you hear an actor make a noise and [...] [tvtropes.org]