The answer, of course, is that if you start with "hash marks all over Amy's face" as a plot point and then retrofit it into whatever episode you feel like, which is how this show is written now, it doesn't matter. (And also, because weird stuff magically appearing on your face has already happened like five times in the past four years on this show, so why not.)
Everybody's spent the last three months trying to figure out what is going on here, but as the characters themselves remark, that's difficult when you can't remember what you're doing or why you're there. Instead of following this through to its logical or satisfying conclusion, the answer is again that you can't remember, unless it's sometimes, and then you kind of can, depending. To distract from that mess, let's have a big speech.
"As long as there's been something in the corner of your eye, or creaking in your house, or breathing under your bed, or voices through a wall. They've been running your lives for a very long time, now, so keep this straight in your head: We are not fighting an alien invasion, we're leading a revolution. And today, the battle begins!"
...Don't got it. Canton asks why they didn't just tell him this, and of course they've told him this before but he doesn't remember it because that's how it works, and since the Doctor couldn't tell him all about the aliens and refresh his memory -- despite them spending three months playing grab-ass with him and constantly reminding him about it, and the daily visits to the Doctor in his perfect jail cell which Canton apparently thought was real, until suddenly he didn't and was all of a sudden in on the plot and had never shot and killed the people we just saw him shoot and kill. To distract from that mess, let's have a practical demonstration:
Canton fixes the Doctor's bowtie, because he is gay, and everybody stares at him. He looks down and his palm is blinking, because he's just left himself a message. Apparently there's a Silent in the TARDIS with them that he saw. Except just kidding, it's a hologram that they "extrapolated" from Amy's phone picture, and -- per the recording we're listening to -- the Doctor instructed Canton to look at it, I guess with everybody else turned around, and then once he'd broken eye contact, fix the Doctor's bowtie. So that's what he did, because mind control. So then we talk about mind control for a while, Rory goes, "Ruling the world with posthypnotic suggestion?" and then before that thought is completed, new topic.