Still can't tell the difference between the two .... must be an age thingy or vision is on the decline.... dang !!! Oh to be young again !!!!
I doubt it is related to age. It's more that the statement is odd.
If a woman deliberately goes for looking sexy she'll easily get a lot of attention, but generally speaking this is short-term.
Beautiful can attract much attention just the same, although then maybe from different type of men or slightly different attention. More towards admiration.
But like you say these two are very close together, you can't really separate them, and like Ladywind says: both are in the eye of the beholder.
The OP is also omitting the largest group of women: the ones that are more -let's say- normal. But these can still be found highly attractive, beautiful, and sexy.
And when you find someone beautiful, you usually also find them sexy.
Which leads back to the statement being just weird and doesn't make a lot of sense. But maybe this is how it works for the ones that are more shallow and not looking for love and commitment?