As the person who is normally The Diversity in any professional setting: it REALLY depends on the context lol. Like I work in tech in silicon valley. A large chunk of the people at these company are white (Americans, Canadians, Australians/New Zealands, or Europeans), but there's a TON of east Asians (China, Japan, {South} Korea) and Indians. So when we talk about "diversity" in regard to race in tech hiring, not only do we mean not-white, we also mean "we should probably look at people from other countries/backgrounds, too." Which means BIPOC (the actual definition of it, which is asian-exclusionary), Hispanic/Latino etc. And other parts of Asia, like the Philippines, the Hmong, Indonesia, etc.
For gender/sexuality stuff, it's not just people who are queer, it's people who do exist within the binary but aren't necessarily fitting into gender expectations. Like if women are allowed to have painted nails, can a man? Are women allowed to wear pants? Can they get away with not shaving their legs?
When it comes to stories, I don't really notice if a story is diverse anymore. But I DO notice if it's NOT diverse. Like when someones skin color is only brought up when it's not white...gee, why would you do that? Is it because you assume that white is the default and it's only worth mentioning when it's something else? Or when a gay person exists but only as The Gay Best Friend. Or the hair dresser. Like I love Legally Blonde, but it is gross that gay men only exist as a joke (like in the bend and snap scene) or for plot connivences. Like haha a man will only know what brand a shoe is if he was gay! Because straight men don't give a shit, am I right, ladies???? But gay men can be other than lispy, effeminate, catty gays. Including only that is like...congrats, you barely tried. I'm not counting this as diversity, though, because it's lazy and offensive.
I'd probably consider a story "diverse" if someone would be mad about it. Like a trans person existing and their whole story isn't about them suffering. Or lesbians/wlw existing and it's not to titillate straight men. Or any sort of "diverse" person existing and they're just vibing and the same as everyone else. Like the gay rat wedding in Arthur, or And Tango Makes Three, or whatever.
Oh yeah, another type of diversity that does exist but I don't think really counts as diversity is what I refer to as [
Burger King Kids Club] diversity. This was really popular in the 90s, where you'd have a group of kids doing stuff, and you'd have one of each: Normal guy, black guy, asian, kid in wheelchair, nerd, Girl, and dog. Like how Mighty Morphin' Power Rangers had black guy, asian girl, nerd guy, normal boy, and normal girl. And, of course, by "normal", I mean cishet white and into activities that are normal for their gender/race/class. Like sports and cheerleading. Doing "diversity" like this is doing a one-of-each approach, instead of realizing that, you know, black girls exist. Black nerds exist. Making a separate person for each "group" pf people to like is lazy and gross.