This was written before it was quite clear how the plot worked…
As all the mirrors in the room [square & round] are very carefully placed to always show us multiple reflections of Alice without needing to either CGI out the camera or CGI in another image, then it makes that shot the only CGI shot in the entire scene.
I'd call that pretty intentional.
[I've only watched that one scene, from the point she starts running the bath, so I don't know how it may relate to the plot].
Now I've actually watched the whole thing, I think it's both a simulation glitch… and an unexplored sub-plot. It appears to have no connection with any other 'flashback' or 'dream' sequence in the movie. It is one of many increasing instances of 'mental cutaway' we're shown as we're led closer to the reveal, but it seems unlike any of the others.
I would be tempted to call it 'bloody-minded non-revelation', as right the way through there is obviously something 'wrong' with the idyll, yet the 'clues' we are given almost never point towards the actual reveal [which I will not reveal, in case others might like to watch it].
This particular glitch appears to have absolutely no relevance to anything else in the plot.