I am in a 1 year internship right now at Prosthodontics practice. The practice has an in-house lab. I have been working there for about 2.5 months now and work mostly in the lab under the supervision of the lab tech/manager. Some of my responsibilities include pouring up models, trimming models, articulating cases, making temp shims, diagnostic wax-ups, custom trays for crown and bridge, implant and denture cases, base plates and occlusion rims, processing dentures, etc. I also help in turning over rooms with the assistants, help in sterilization, some patient scheduling. Hopefully soon I will be able to do some assisting. It has been a great experience so far!
Good luck with the interview! I imagine that any kind of internship at a dental practice would be a great thing!