Two adjacent edges are yellow on top, forming an L with the centre. Hold them at the front and on the right.
Algorithms
f R U R' U' f'
6 moves
YOURS
Built from
f + Sexy move + f'
Loose moves
f
Trigger
Sexy move
R U R' U'
Loose moves
f'
Part of
OLL 2
OLL 3
OLL 4
2-look Dot
Relations
Your algorithm backwards
f U R U' R' f'
solves 2-look Line
That's why your scrambles are never the inverse of the algorithm: you'd be practising Line without knowing it. CubeDojo builds a random state with this case and checks it comes out.