She's the superlative. She's the StrongEST, baddEST, bEST, fastEST, greatEST... whatever word you need to utilize, she's its the vast of majority.
I envision for the most part positive words.EST is the closure of different words she uses to portray herself.
Like fastEST. Most baddEST you get the point.
So when you hear for example a WWE commentator say the EST OF NXT IS L.I.T like during the 2019 survivor series, then you should imagine it like, THE GTREATEST OF NXT IS LIT.
NXT itself mean next generation, so the stongEST, bEST etc of the next generation.