I suppose how Pam smells would have a lot to do with what she had recently eaten and where she had been. (And even what she had been doing while she was wherever she had been!) I suppose the variety of possible smells is endless.

In answer to the question, Why do people in the metal life sniff Pam? Probably because her sister was already occupied elsewhere! I wonder if her last name might be Tams? Pam Tams?