This is what always bothered me a bit.
We all agree no one can look better than Catherine. Unless someone is as tall and slender and perfectly coiffed, they will never look as good, standing next to her.
Catherine knows this. Now what. She gains some weight, she loses her waist or whatever medications may do (just hypothesizing) - she'll not be the epitome of what people glorify about her, must be hard for a person who is constantly compared as visually superior to another woman.
That's why I always felt uncomfortable when people would post side-by-side comparisons of Meg (for example) and Catherine. Her fans put her on such a pedestal and it may be difficult to not be able to keep up to those standards.
In other words, too much attention to Catherine's appearance, IMO. Gorgeous, yes, but what happens if she loses it somewhat.
I think anyone who loses good looks feels the loss...but Kate strikes me as a perfectionist and I don't think she'll want to be back until she can do (and look like she's doing) everything perfectly.