I was just watching this episode and was thinking the same exact thing! This might be some sort of head nod to muse. Also, I notice there was a coffee shop in the second episode or earlier named "Honoka Coffee". I wonder if there will be a cameo of her in season 2 or some sort of recognition of Muse and Aqours.
I watched until EP2, but I'm still trying to find time to watch due to schoolwork, as for my favorite idol.... Well it's usually Kanon, but I love all of them!