A bit of a stretch but hear me out.
Nami smiled at Vivi in Alabasta bathhouse.
In an SBS, Oda said that Nami's favorite stuff are money and beautiful women. Hence why we got the whole "Lesbian Nami" debate around.
There's theories speculating that Nami is related to Imu.
Imu holding Vivi's poster and have history with Nefertari D. Lily, the first founding King or rather, Queen of Alabasta.
We know that the term "King" can be a woman, seeing how Lily was part of 20 Kings that fought against the Ancient Kingdom and formed the World Government.
So connecting all these together, Imu is related to Nami (Imu might even have Nami's appearance) and Imu is interested in Vivi because Nami is also interested in Vivi.
Man, can't wait for Oda to bomb this theory and introduced us with bratty spoiled snot nosed ugly shota as King of the World.