So the recap implies that it was the plan all along for Worf to project a false Federation ship onto the Ferengi ship's sensors — but if I recall the episode, the Ferengi simply said they detected another ship (actually the Hathaway), which they presumed to be another functional Starfleet ship dropping out of warp entering the sector seconds after the Hathaway was "destroyed" by the Enterprise. There need not be any projection onto the Ferengi's sensors at all.
So the recap implies that it was the plan all along for Worf to project a false Federation ship onto the Ferengi ship's sensors — but if I recall the episode, the Ferengi simply said they detected another ship (actually the Hathaway), which they presumed to be another functional Starfleet ship dropping out of warp entering the sector seconds after the Hathaway was "destroyed" by the Enterprise. There need not be any projection onto the Ferengi's sensors at all.