i think what Oglu meant when asking if it's an "inhouse test" was if you are already in the studio and it's just a test to transfer to a different department / team.
You'd be expected to do this in a day. Like, you have 4 hours to do all the sculpting, then send your finished sculpt. And then 4 hours after that for texturing, lighting, etc... But that's just speculation based on the art tests I've seen. On a side note, the art test I did to get my current job 6 yers ago was a 1 hour…