I don't know... I used to go to a very small office that sounded very similar. The waiting room was about as big as my kitchen and had three chairs. Usually it was just me. The receptionist was there, but was behind a glass. My pdoc was very friendly and sat in much the same fashion as your describing here. It was called the "City Clinic" and was part of a larger network but was just the smallest clinic in the network. I loved that particular pdoc. I did also see a T in that clinic, but I used to have pretty lengthy conversations with my pdoc when I saw him and new he actually cared about my progress. The only reason I stopped seeing him is because he switched to only seeing inpatients at the psych hospital they're all affiliated with.

Maybe dig a little deeper--are they affiliated with a larger network? Is he affiliated with a hospital? It's probably totally legit and having more information to back that up will make you feel better about it.