Confused here too, but I can see how OP might be thinking about it. At least this is how I see it working.
The way I see it is you could have someone on an actual contract. Like can’t work for another competitor. Also they are always on call, like if you have an Animator in a small studio, they’re may not always be work for justify a full time guy. But when you need them the office they are there. No sorry I’m not avlaible this month.
Maybe the workload of the office doesn’t justify 40 hours a week and they offer that specialized role. Like the consultancy use to get a ton of packaging projects and had a full time packaging engineer. They loose that long term full time client. Packaging engineer now can either be let go, or transition into another role. Or they stay on and do packaging “part time” on the smaller clients that the studio now gets in. So they come in 3 days a week instead.
But I mean it would have to be a very special circumstance. Something that evolves. I can’t see someone just getting hired like this off the bat.