Mama feels like the most rebellious song in the shows we've seen so far. Between the dagger outro and the way Gerard acts right before it in San Francisco, laughing and saying "hello my beautifuls" it feels almost like their seeing the audience properly for the first time that night. Its a lot more similar to how they acted in Seattle and a lot different from how they were acting earlier in that show, like having to read that ad really cut through whatever recondition is happening. Plus they take their jacket off for it and keep it off through Sleep but once they get to Teenagers they are forced to put it back on.
Mama really seems like its, very literally, being highlighted. Everything about it is different than any of the songs that are before it, the lighting, the tone, Marie-Anne, the background, there is always a clear shift into them playing Mama and then out of them playing Sleep. Add this to the static that fills all the screens between Sleep and Teenagers, I raise that maybe Mama (and perhaps Sleep as well?) is for some reason not supposed to be played, like its the one song that Draag doesn't want them to perform or that they can't twist to their agenda, and them continuing to play it is one of their small acts of defiance against being Draag's puppets.