"Hera" was the code name given to Poppy's half of the new expansion, comparable to Ian's "Zeus". For a time in the project, she split off from Ian, even moving into separate offices, to hash out her plan. While the exact dimensions of her half of the expansion weren't fully known, it seemed to centre on a water environment and an attempt to, as Anthony put it, break the laws of physics by having more players interacting than anyone had ever done.
Dana was on team Hera following the failure of Grouchy Goat in an effort to get Poppy to teach her how to become a master coder.
Ultimately, Poppy was really using Hera as a way to surround herself with people whom she hoped would give her the same creative stimulus that Ian did.