Excerpt from the DS9 season 2 DVD box, special features: "To give them [female Cardassians] something a little different, because at the beginning we thought 'How you gonna tell them apart if they're not wearing a dress', was to take and paint the center of their spoons at the center of their forehead, to paint it blue.
And then we picked out the second or third rung down on their neckpiece and that was also painted blue.
by Jrg Hillebrand and Bernd Schneider Sexual dimorphism (see the definition at Wikipedia) denotes a systematic dissimilarity between individuals of different sex in the same species, beyond the obvious difference of male and female sex organs. In many species of birds the male form bears a more colorful plumage than the female form, the peacock being a prime example. It is plausible that the average males of most humanoid alien species in Star Trek are taller than the women, as they are played by human actors or actresses, respectively.
This may be a considerable sexual dimorphism, but she could also have been an offworlder who came to Tiburon for her despicable experiments.
Since the recreations of the Excalbians were crude (like that of Kahless), the real Zora may have looked very different anyway.
The blue markings, especially the one on the spoon, may be the Cardassian equivalent to eye shadow.
Michael Westmore's original intent would allow this interpretation, however, the perpetuity of the make-up on Cardassian women suggests that it is indeed a natural feature.
These bulges are less prominent on the Vissian women.