Hi, not gay but bi and I spend a lot of time in LGBTQ spaces. I personally have not heard of this meaning anything specific. Chances are that it’s just a quirky / goofy expression that they like. I have a few friends who are not gay where every photo has a similar expression, it’s just something some people do I guess 🤷

I think what OP is trying to say is that people in their age range will end up being the last of those people, ie. the internet was one of their earliest memories and that happened to be right as it took off. A similar example from my age range, we will probably be the last to remember the WTC attacks as they happened. It’s one of the earliest memories I have. Not me specifically, unless I am graced with an incredibly long life, but someone around my age who is.