I had trouble comprehending it towards the end. If... Miyuri had wanted to become an actress, could Machi have continued fooling herself to continue acting due to the notion of rivalry?
I'm guessing that's what she wanted, some kind of excuse to stay true to her childhood ideals.
I guess finally picking something definitive that's not acting is sort of sealing the deal, but Machi was already on her way to resigning anyway. I suppose this just removes the very last, tattered shreds of that dream, and ending any more notion of rivalry.
It's somber, if that's the case, but... also life. Sometimes you put in all the effort in the world and fail... sometimes you just fool yourself into thinking you are. And I think some people keep those lies at bay forever, thinking to themselves, "I definitely could have done it if not for x and y." to their dying day.
...well, it's something to ponder about. Now let me get some HOT DOGS