She is naked

Amy: Who the hell are you?

Amy: I'm you. From your future.

Doctor: Tell me exactly what's happened.

Other Amy: Well the exterior shell of the TARDIS has drifted forwards in time. If you step into the box, you venture a tiny bit into the past.

Amy: I don't understand.

Amy: Neither do I

Amy: But you said it

Other Amy: No I'm just repeating it. I'm just repeating what I heard myself say when I was stood where you are now, I'm just repeating this too. And this. And this.

Amy: I still don't understand

Amy: You still don't.

Amy: And why am I, why are you naked?

Amy: Because I saw myself do it

Doctor: Okay when does this Amy enter the box? We need to maintain a timeline.

Amy: As soon as she takes her clothes off after she slaps Rory

Amy: Wait! Why do I have to be naked?

Rory: And why do I get slapped?

Doctor: Because we have to stick to the established chain of events. One mistake and the whole timeline would collapse. We'd end up with two Amy Ponds forever and then what would you do?

Rory looks at the Amy to his left with a suggestive look on his face. She is appalled and slaps Rory square in the face.

Doctor: Okay you. Into the police box now!

Amy runs over to the blue box. Stopping at the doors

Amy: What and then I become her?

Doctor: Yes!

Amy: And I need to...

Amy: Strip!

Doctor: Yes go go go!

Amy begins to blush and begins to take her clothes off. First her shirt, then her skirt and her boots and tights followed, talking to the other Amy as she does this.

Amy: Do I really look like that?

Amy: Yeah. Yeah you do.

Amy: Ooh, I'd give you a driving licence

Amy: Oh I bet you would

Doctor: *exasperated* This is how it all ends. Pond flirting with herself, true love at last.

The Doctor looks to Rory who is staring open mouthed and unblinking at the sight of two naked Amys.

Doctor: Oh sorry Rory.

Rory: Absolutely no problem at all.

Doctor: Now Amy!

Amy now completely naked from head to toe.

Amy: What's the first line?

Amy: Okay kids, this is where it gets complicated.

Amy: Gotcha. *shoots her a grin and a wink and struts into the box. The door closing behind her.* So is that it, are we safe now?"

Doctor: No we're still trapped.