This was a commission for darienmerced, so you have him to thank for this concept.
It basically theorizes that Cozy Glow was Zipp and Pipp's great grandmother and the first queen/founder of Zephyr Heights. Cozy was also possibly one of the few individuals responsible for the three races breaking apart. Adding on to the concept, though she had long since passed away, her presence can at times still be felt in the castle. And she uses her will to entice her great granddaughter for some sort of nefarious purpose.
By the way, in case you’re wondering why Pipp’s eyes are red instead of green, it’s all apart of darien’s concept. Pipp eye’s were going to be red in her original design, and he theorized that she was possibly related to Cozy Glow for that reason. Personally, between that and the vintage aesthetic that both characters possess, I’d say it could have some legitimacy behind it.