Functional social skills
Any workplace is a social environment. People do have to work together. At entry level, being shy is understandable. Being a hermit, however, isn't a social asset to the organization.
You prove social skills by your presentation, and being communicative in a meaningful way, not just going through the motions. Any social environment is a constant supply of communication, direct or indirect.
The idea of a fit to a job is actually very accurate.
Some people are truly lousy fits for some organizations, and it's partly because they have the social skills of rocks. They don't do much, they don't say much, and getting information out of them is quite hard work.
At the interview, remember these are people you're going to be working with.