The ending is explained BEFORE what most people think
SPOILERS obviously
After all the mishmosh of theories of the ending I watched this for the first time today and realized that everyone is confused about the ending because they interpret his "death" from the SECOND time he shoots himself on stage.
He shoots himself for real when he is standing on the stage in his underwear.
If you watch it from that point on you can see several things.
First there was foreshadowing up to that point. He points out the importance of structure with his discussion with the critic. But as for us as the audience let's take note. The foreshadowing was when Edward Norton's character got angry with him for replacing the real gin with fake gin. Norton's character is an opportunist who is willing to do anything to get the attention he wants. So he replaces the prop gun with a real gun.
Second, backstage he winds up locking himself out because of all the chaos and disorganization. This shows us that the workers are sloppy and not paying attention. Because he comes on stage from the audience, someone rushes out and hands him a gun. So he didn't take the gun with him. Notice there's attention drawn to the fact that he's holding up his hand like a fake gun. Naomi Watt's character even says "put down the gun"
Someone just slaps a gun in his hand (we don't even see who) and he storms to the front of the stage to finish the scene.
Then the camera pulls away.
Notice, there's constant chaos in the Hallways behind the scenes in every other scene before this.
But when he walks onstage from the audience and is just about to shoot himself, the camera pulls away and lingers on the hallway for an extended period of time.
The filmmaker takes a looooong time sitting watching the empty hallway. Why?
Where is everyone? They are all on the stage attending to him because THAT is when he really shot himself.
Listen again, you hear the shot and then you hear applause that suddenly just stops.
Then he walks back into the room and we follow him up with blood on the back of his shirt. When he gets in the room he sits and talks with his daughter. (Why is she there? And notice the gentle conversation and how we hear her voice before we see her. It's a peaceful scene compared to all the drama before it.)
After that he begins many of the over the top abstract things like flying. Notice that it is an interplay of fantasy with reality pushing it's way in. For example when he lands and walks into the theater, the cab driver rushes up and demands to be paid and we see an open taxi door.
IMO All the scenes after the hallway scene reflect (as someone else mentioned) a similar style of "An Occurrence at Owl Creek" he's dying in these scenes and his life is flashing before his eyes as he's imagining it all.
That's why in the scene with his wife, the camera swoops into the dressing room and he's lying across the dressing tables. The room is filled with flowers just as a funeral home would be.
Watch this again and you will see it looks like a funeral and he's in the position he'd be in in a coffin in a flower filled room.
It also mirrors how we are introduced to the hospital room later.
It's a mish mosh of fantasy with reality creeping in as his "rational mind" rewrites it. You can see an almost "going through purgatory" sense of him walking out of the liquor store and seeing the man "performing" in the scaffolding.
When he replays his life, he tells off the critic, he performs the scene he screwed up in a fantastic way, the audience is on their feet and the critic runs out of the theater.
Even if you watch Edward Norton's character in that scene, he is underperforming the scene.
When he wakes up in the hospital room it is just a moment of him regaining consciousness before he dies. Who is in the room with him? The three people whom he loves the most. His best friend, his ex wife and his daughter. (If he was really recovering, wouldn't his girlfriend be there?)
Then at the end when he looks at himself in the mirror he realizes that he's not the same person any more. Notice at this point he's all alone in the room and then Birdman shows up. This is when he dies and goes out the window. At the end he is reassuring himself that his daughter will be OK.
Notice that she first looks down, and notice that prior to this there was a conversation pointing out that it was an accident, not a suicide attempt. This is is reflected by his daughter looking down in fear that he jumped out the window, but then looking up realizing that he just died and flew away.
(Very similar to the end of American Beauty) A sense of peace.
If you go back and watch the movie from the scene with the underwear you will see that from that point on is where it is that he is dying. It doesn't make sense if you do it from the second gun shot.
The scene where the camera "stares down the hallway" is the "break" and lets us know that everything after that is different.
Feedback is welcome. I didn't go through the entire board and I'm curious if anyone else saw it this way.