"MV acting" is the art of balancing music, set design, and costume during a segment of the MV, so that your actions feel inspired by your current state. Instead of just posing blankly infront of the camera, you move your body and emit facial expressions in a way that will captivate the watcher. It is a holistic combination of modelling, dancing and acting all at the same time to the beat of music and in relation to what your set and costume is.
How is this different from just acting like you would normally? Well, you can't be too overt with what state you are displaying. Because their is no dialogue, the watcher needs to be able to recieve their own interpretation from what you are doing. If you try too hard to display emotions with regards to what the lyrics are, the watcher will feel redundant. You want the MV watcher to interact with the MV, your actions should be abstract enough for them to get their own interpretations.
Examples of idols with excellent MV acting:
2. Chaeyoung Twice (A lot of people say my girl has bad stage presence, but when it comes to MV acting she eats. )
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If I have to summarize, good MV acting is
1. You move your body to the beat of the music, but don't do the actual choreography. (It doesn't even have to be your entire body, but a small hand or finger movement.)
2. Your facial expressions match what the lyrics say, but in a way that is subtle enough way for the watcher to interpret their own meaning of what your expressions are trying to say.
I have more examples but my girl in the stall next to me has diarrhea so I'm gonna leave now. Who do you think is an idol with excellent mv acting?