Traces its roots to the Rochdale pioneers. I'd say it's not just "a" co-op, it's likely the oldest in existence on Earth.
But yeah, working there is not going to be too much different to working at any other store.
Still, don't underplay that. Having something you can go to, walk away from without having to bring home any work, get your 30-40 hours/week (and they'll pay a decent living wage), so you can pay the bills and keep your creative energy for your art... it's not a bad way to be.
Working there is like working any retail job, and a far cry from a small community co-op.