For the internship, there was no phone screening. I was simply brought in to have two thirty minute interviews with managers on the team. The first asked me about items on my resume to get a feel for my knowledge. The second came right in and drew a UI on the whiteboard, then explained what it should do and asked me to design the software. It was pretty open ended. Afterwards, they walked me out and that was it. All I can say is be prepared to answer underlying design questions.