I always notice that certain items or locations get used in other AVN's. For instance, the kitchen in Young Again is the same kitchen used in Halfway House. The travelling bag used by one of the girls to go on the workplace holiday is used in Welcome to Free Will. The rug in Emma's bedroom is the same rug in the living room in My New Memories. There's numerous other examples littered throughout the various AVN's.
It's as if the dev's are dropping the hint that they're linked and working for the same group of pornographers. I suspect the little hats, especially given that many say English isn't their first language, and they're also the ones predominantly pushing porn in the West.