White plays and wins in 2 moves
- gxf8=Q+ Kh7 2. Qg7#
The analysis board does checkmate in 5 moves
- gxf8=Q+ Kxf8 2. Bxe6 b3 3. Bxb3 Ke8 4. h7 Kf8 5. h8=Q#
Source:
This publication is in my collection "500 chess puzzles. Mate in 5. Advanced & Expert Level."