[Pair with next print]

Harunobu is here showing us a parody of an old Chinese tale involving historical figures. Wikipedia has the story, which involves a bridge and a tossed shoe (here represented by the fan she is holding). Educated Japanese of the period when this print was issued (mid 1700s) would have recognized the allusion with no problem.

(Having said that though, there still remains the question of why his saddle should be marked with the 'Genji Mon' for the Matsukaze chapter of the Genji Monogatari ...)