Yeah. I kind of saw haikujaguar's word of the day Wednesday and said to myself, "Yeah. Jayce does indeed cosset Izzy." He's got reasons, but still... So that was part of the reasoning for having Aunt Gladys be stricter.

As far as she's concerned Izzy may be a favored slave, but he's still a slave and therefor doesn't belong at the table. Family and guests only, anyone else better be there to serve the meal.

And of course there's the unspecified threat to give both a reason to remember.