Original Commentary

Burr is, of course, the sound that Brent makes. It's kind of an angry purring sound. When Sofia doesn't dote over him, he sounds even angrier. I'm sure Ms. Taylor is trying for the mother-daughter experience and since Kimberly isn't really receptive to that, she's moved on to Sofia - Isabel

Modern Commentary
"A Brent Bag?", you say, "But Brent is the name of that specific brant, not the name of his species. She should call it a brant bag"

We hadn't named brants at this point and wouldn't for another eight months. - Terrence