I understand what you are saying but we need to remember , Marti, like Justin , represented the Sung Thoughts of The Journalist , meaning that they were not playing the part of a 'live' person because that would have confused things. So prehaps it would have made sense to 'stand still' and just use the voice for the beautiful song.
I saw Marti and also saw Justin and both did exactly that. they did not act in any way whatsoever.
Does that help?
"I got a plan..."