Updated Aug 19
Thanks for the A2A.
In the second-to-last episode, Old-William/MIB thought that Emily was a host, sent by Virtual-Ford to manipulate him.
MIB killed Emily, and then saw the metal or plastic card in her hand.
My guess is that, these cards are given to guests as an emergency identification (if they are in danger, or if they need or want something). Back in Season 1, MIB had a way to communicate with the control room, when he requested the exploding cigars during the jail breakout. Secretly, this card is also storing video recordings of the guests’s actions (Old-William knows this, brings it home, and that is the card that Juliet finds). In Season 3, somebody will find Emily’s card, and view it.
ETA: Maybe that is actually MIB’s card that Emily has in her hand. In that case, maybe MIB had left it at his house, then she found and viewed it, and brought it with her. This is MIB’s indication that Emily is his real daughter.
Anyway, this shows MIB that, he just killed his own real human daughter. He is distraught, with nothing more to live for.
MIB stands in the field, and tries to shoot himself in the head. But he starts thinking about his choices. Were they ever really his? He started out life as a human, and, at some point, he wasn’t anymore (possibly from the first visit?). He is choosing to kill himself? Or he is choosing not to? Remember his speech to Lawrence in S1 (“No choice you ever made was your own. You have always been a prisoner. What would you think if I said I’m here to set you free?”)
When you are in the dressing room, you choose your hat. White or black? Good guy, or bad guy? William converted himself. Maybe the recording mechanism is tucked into your hat, to see if you were really the good or bad guy that you thought you were?
MIB thinks that maybe that he is being coerced and ordered by somebody else (Virtual-Ford?). He is worried that his personal choices have been manufactured.
MIB also thinks that there is something inside his right arm. It is either coercing him to pull the trigger, or coercing him not to. Perhaps two conflicting signals, from different sources. He cuts his arm open to look for host machinery, and is trying to dig out something like a USB connection. Thinking that he is a host, maybe he is trying to disconnect himself from the Mesh broadcast/control system.
ETA: I just changed some of the above speculation. As per another user’s response to this post, I Googled and found this interview with Lisa Joy which indicates that MIB isn’t proven to be a host at this point. And that, the after-credits scene is in the far future. It also indicates that I was right about Stubbs.
That is when Dolores/Wyatt arrives, and orders him to follow her.
Compare something. Just after that, Dolores/Wyatt places a piece of metal into one chamber of MIB’s gun, before handing it back to him. She already knows what he will attempt. When he fires on her, she has very similar movements to S1,E1, when MIB had the bullets bouncing off of him. And the gun-to-forehead moment echos that similar moment with Teddy.
The finale also had a brief glimpse of MIB in what looks like a training or interview room at The Mesa, with a very displeased facial expression.
In the finale, the Delos Corp rescuers place a scanner to the back of MIB’s neck, and confirm that he is human. However, some hosts can be set to falsely “read” as human, in the perception of another host (didn’t they do that with Clementine’s demonstration in S1?) MIB is the newest, most expensive, and most advanced host body.
In the bit after the ending credits of the Season 2 finale, MIB stumbles back, up the lift, then into a replica apartment, with his real daughter, Emily. They do the “fidelity” interview. Note that, MIB’s hand has already been injured, from when Dolores clogged his gun, causing it to explode. That means that, their confrontation (and the prior moment with MIB holding the gun to his head?) has been replayed many times.
My guess is that, when guests sign the contract, pay the fee, and commit to going into the park, they have something implanted (“It was built in from the start”) and this not only uploads behavioural data, but is also about trying to make host copies of every guest.
Every guest is has a recording, represented as a book, and as data with potential host-body-loading at The Forge. Dolores wants to infiltrate the mainland, and publically broadcast every guest’s recordings.
The host consciousness (e.g. Maeve), and the guest-to-host conversions require two things for them to work. First, you need a “cornerstone” of grief and suffering. MIB has Juliet’s death (Shakespeare’s Juliet?). They also require some kind of evolution. A mistake in which the copy isn’t perfect, and thus becomes a new species (Bernard is different to Arnold).
Teddy actually isn’t dead? Although, the way that Dolores cries seems to be a repetition of a tragic loop. So, maybe he isn’t actually dead.
MIB is alive, awaiting medical evacuation.
Note the conversation where Stubbs tells Charlotte that, he was hired by Ford, so long ago that he cannot remember. This suggests that Stubbs is also a host.
A certain Dolores body really was shot and died recently. Although, this may have been part of a repeating loop, which resets. Although, I strongly expect that, Evan Rachel Wood will be playing a different Dolores body in Season 3.
Dolores’s consciousness has uploaded into a host-Charlotte body. Old-William will be meeting her in a Delos Corp boardroom, in the first episode of Season 3.
ETA: I still think there is something physically inside William’s right arm. In this speech to his wife, from S2, E9, he rolls up his sleeve, and is looking and feeling around on his arm.