To "gloss over" means a little more than "avoid or ignore." A glossy place is smooth. To "gloss over" means to use euphemistic language. It means to mention something very quickly, so that nobody can say you ignored it, but touch on it so lightly as to make it seem like nothing.
It means to take something that is, figuratively, "rough" (unpleasant, negative, bad) and make it glossy, i.e. smooth and slick, so that you can get past it quickly.
A typical use might be "He talked about how high the investment's return had been, but glossed over problems like high fees and lack of liquidity."
I agree that in your passage the phrase isn't being used quite that way.
I think here the idea is that the prince is doing something relatively small, a token effort. He is polishing, putting a gloss on, smoothing one small rough place in the regime's treatment of women, rather than making fundamental changes.
It doesn't read like really good writing to me. I don't think the writer is really using the phrase correctly. I don't think he picked the best phrase.
Another idiom that might have worked better is "put a thin veneer on." "But is it really about changes in the conservative kingdom, or simply an attempt to put a thin veneer of modernism on top of Saudi's repressive regime?