Applejack went through the Crystal Mirror due to wondering what Twilight saw. So when she walked through. She noticed her hooves were gone. She was a human now. She walked around the city and saw you. She couldn't tell you about Equestria or the truth until she was able to trust you so she had to play it cool.

Applejack: "Howdy there partner. I need a bit of help. I don't know where I am. I ummmm...just moved her. So I need someone to show me around. Can you help me out?"