This detail in the painting has raised profound questions. Does it celebrate the marriage of Alfonso d'Este and Lucrezia Borgia? She is holding a quince, which is the symbol of marriage, and indeed there is some resemblance.
These figures have an awkward appearance. Were changes made, if so what? By Bellini or Titian? We conclude that the right hand was altered—by Bellini not Titian. None of Bellini's orange dress paint is found under the hand on her thigh.
Neptune (Alfonso)'s right hand was on his chest not Cybele (Lucrezia)'s thigh.