I went to see this sequel to Pixar's Finding Nemo largely because, well, Ellen DeGeneres plus a rumor that there was a lesbian couple somewhere in it. OK, and I have a certain local pride in Pixar, despite their usual tendency to make boy-centered films. (See my review of Up for a discussion.)
I confess that, in the previous movie, I found the character of Dory annoying. Scatter-brained, easily distractible, hard to keep on track. And I say this with some discomfort because a number of people very dear to me have those characteristics and, yes, they do drive me crazy. But Finding Dory turns the story around, and rather than Dory being the funny side-kick, now she's the protagonist. The basic plot is: at some time previous to the earlier movie, Dory got separated from her parents. She no longer remembers how or why, or has any idea where they are. All she remembers is that she'd like to find them again some day. And then she starts getting flashes of memory...
Similarly to Finding Nemo, this is a quest story with lots of helpful side-kicks, adventures, peril, and improbable success. What gives both movies a lot of heart is the underlying theme that you can't protect your "different" children from the big, bad, world. What you need to do is give them the personally tailored skills to succeed on their own. Nemo's over-protective single dad wouldn't let him learn to cope with his malformed fin. Dory's parents, in contrast (as we eventually come to realize), did a very successful job of beginning to teach her practical coping skills, and giving her a supportive environment for moving toward independence. But at the beginning of the movie, all she remembers (other than the matra, "I have poor short-term memory") is that it must have been her fault for losing her parents.
The superficial story is the usual roller-coaster ride of improbable slap-stick adventures. The animation is gorgeous, of course. There were times when Pixar seemed to have leapt nimbly across the Uncanny Valley and produced backgrounds that felt photo-realistic. (I felt this even more so with the short that preceded the main feature, following the adventures of a sandpiper chick learning to interact with surf.)
As for the rumored lesbian couple: knowing that they were supposed to be there somewhere in the background, I think I noticed them flash by during an acquarium crowd scene. But if you didn't know they were supposed to be there, I don't see how you would realize it. Not exactly what I'd consider representation in a practical sense.
I'd be very interested to know what viewers who are themselves non-neurotypical think about Finding Dory and how the character is presented. My impression was that there was very little "making a point" going on, and that Dory was a fun, realistic, loveable, and sympathetic character. Not a clown being presented for other people's amusement. But, as I noted above, I'm not viewing the character from inside, so I may not be the best judge.