Up until then, Riker was attracted to very feminine looking women, so when an androgynous person with no figure comes on to him he immediately responds.
The character of Minuet in "11001001" and "Future Imperfect" was supposedly Riker's perfect woman, actress Carolyn McCormick (Minuet) and actress Melinda Culea (Soren) have almost identical figures.
Minuet was more fashionably decked out (dress, make-up and hair), but the two women are surprisingly similar in appearance.
They may have shared a similar body type\figure, but I don't think they look very much alike, otherwise. But it is interesting that both Culea and Dwight Shultz were on the A-Team. What is even more interesting, neither look anything like Troi.