Are women getting more beautiful, or has men's ideal of beauty changed?
Probably a bit of both.
It's clear beauty standards change, however, I think there has been a certain shift with medicine, cosmetics, modern media forever grinding away on fashion, the cumulative effect of X generations with modern medicine and sanitation over time.
Most standards of "beauty", at least as defined by the male perspective of women is based on health and fertility. While this obviously has some variability, "fat" might be beautiful where famine/starvation was common, or "skinny" might be beautiful where there's an over-abundance of food and being overweight is unhealthy etc. So while there's a lot of factors and a great deal of range, I think the elimination of certain diseases, and as certain "hard ways of living" with manual labor that are hard on the body disappear in the post-industrial revolution era, "net-attractiveness" is probably on the rise.
