Does Penn ask major-specific questions?

Peers from my HS who applied to Penn were assigned in-person interviews, while I was assigned a skype one with somebody who majored in the subject that I intend to.

Should I expect some major-specific questions?

Possibly – they interviewer will know the major that you listed on your application, so they might ask some general questions such as “Why are you interested in this major?” and “What is your intended career path?”