Currently scrolling through a few thousand firefox screenshots over the years and the way they're named across different websites is inconsistent, sometimes even spacey, punctuationy or the worst case, both.
I think it's just using the <title> tag to do this. Only some websites add a hint of what platform you're on at the end of the title. Reddit screenshots for example have the subreddit tag as the last word in the title, making it somewhat easier to filter them out. But those keywords also appear in other screenshots even sometimes also at the end. Then some of them just don't tell you at all.
I got a few hours into a python cv2 solution a few months ago for scanning each of these screenshots for common platform giveaways and putting them into an appropriate folder before getting distracted by whatever else was going on that day.
But I shouldn't have to write that. Can we put some metadata in Firefox's screenshots with at least the (+sub)domain the screenshot is from or something? Maybe even a timestamp too even though that is currently in the filename.
Metadata is king.