At its finest

[Men_deurXD]

What does "At its finest" mean in the conversations below?
1st conversation
YouTuber: *blatantly takes another Youtuber's idea without credit/permission*
Sarcastic commenter: "Originality at its finest!"
2nd conversation
Sophie: You're smart but terribly ugly!
Debbie: Woah, Toxicity at its finest!

(The 2nd conversation was just my own idea to create a context connecting the phrase I asked... I hope it's grammatically organized for you guys)

 

[owlman5]

It means that something is the best possible example of its kind or class.