Oh, God. It’s kind of a nightmare question.
I still think Andy is the protagonist. Even if the goal is to “be what is expected of you” or something similar, nobody else is pursuing that like she is — she pursues a makeover, she drops personal commitments for her job, she pulls out all the stops to fulfil the unpredictable demands Miranda foists on her. As for commenting on it, she constantly comments on these demands — she vents so much that Nigel tells her to stop whining, she considers the “clackers” and the dieters to be weird and bizarre, she comments on how silly the debate on the identical belts is, etc.
Likewise, I just don’t see any other candidate for antagonist than Miranda. And I see that it’s awkward because Miranda doesn’t necessarily “win”, but she’s the only one actively (intentional or not) preventing Andy from living up to expectations because she is constantly throwing in those roadblocks — get me the unpublished Harry Potter manuscript, tell Emily you’ve taken her place on the Paris trip, etc. There’s also several sequences where she basically forces Andy (and occasionally others) to reconsider her place in this business — the ‘cerulean sweater’ scene; her pursing of the lips forces James holt to abandon his designs; she makes her staff reconsider their ideas for the spring issue (“florals? For spring? Groundbreaking.”); her ‘hire the smart fat girl’ speech, etc.
It’s tough because I also don’t feel that Miranda ‘wins’ at the end. However, that could be because the IC Miranda throughline changes and they overlap, which complicates things. And I agree that they’re all complex characters which also makes things harder.
I’m open to hearing an argument for Miranda as protagonist, but I’m not convinced yet.