Original Commentary

And here we see Brisbane's fixed-up illustrious apartment. By the by, when Robert mentioned that the apartment was furnished, he meant the wastepaper basket and the chair that Brisbane is currently using. Everything else, Brisbane brought with him - Isabel

Modern Commentary
It's Sofia! Brisbane's sister, from Unlike Minerva (and from the first week or so of this comic [and the flashbacks involving Brandie]).

I'm pretty sure we had always planned on bringing Sofia back, or at least had been open to the idea when we could justify it. We didn't have her show up in flashbacks periodically just so folks would remember that Brisbane had a little sister, but it worked out nicely. - Terrence