Why is it that sometimes the AI tools (I have used Firefly 2.0) seem to generate the "same person" or very similar looking people multiple times? Aren't they trained on some huge number of different images?

I just started with Firefly, for fun and entertainment.  I noticed that when I changed the settings, Intensity or Strength, I often got what looked like the same "Seed" information in the next set. Then the set after that, maybe a repeat of a different version. They might be slightly distorted or the background might change, but the results are not nearly as varied as DALL-E or Night Cafe'.

I also in my early viewing and experimenting, have found that Firefly doesn't have a great depth of knowledge on obscure subjects. It doesn't react the same way as others do, to style commands.

And for anyone reading this who hasn't used Firefly IT DOESN'T SAVE WORK OR CREATIONS! I lost the first hour of work, when I decided to download some, and discovered, closing the browser, loses all links and cache. Then I stared some as favorites and came back the next day, those are gone too. Save as you go!

But yes, I see similar images, even when I'm changing the prompt and when I'm using my own uploaded original start material.