Physical Taunts, or emotes, are the result of using the taunt command (bound by default to "J" on the keyboard). When taunting in this manner, the camera switches to third person like it would while repairing, centering on the pilot's mech as it performs a particular set of motions. Taunts are different for each mech class and there are numerous taunts available per class. Note that taunts are not universal (they cannot be applied to all eligible mechs after being bought, only applied to the mech who was selected in the garage when the taunt was bought). Besides the default taunt (1 taunt is unlocked by default for each mech class), all taunts cost 178 MC to unlock.
Taunting may also be performed while on the post-match Carousel, among other actions.