Search "butterfly lips" and you'll hit two versions that don't match. One injector-training write-up describes a lifted upper-lip centre and a sharper Cupid's bow. A clinic guide instead talks about fullness spreading toward the corners for width.
Same name. Different shape. That's why the word alone is a weak brief.
Before you use it in a consult, ask which version they mean. Bring a photo of the look you like, not just the label. Front and side if you can — width and lift don't show the same way.
There's a short page that lays out both readings side by side: butterfly lips explained. Useful when you want the name to stop floating.
Sofia R., LookPrep