Don't want to speak for Annie, but when I ask myself what I consider to be "lean" vs. a little more muscular or bulky is looking at Cathe's look over the years. When I think lean, I think of the way she looked in the Body Blast series (what I wouldn't give to have that physique!!), while she's much more muscular in the STS series.
Please understand I think she looks BEAUTIFUL both ways, but objectively speaking, it's pretty clear there's a difference in her physique, and for my personal body type, I think the leaner look would look better on me than the muscular look.
I definitely don't think the waif look is for me LOL; I love having defined muscles. But I do think there's a continuum in musculature, and I'd prefer to be on one side of the continuum vs. the other.
(I feel I must repeat before I get misunderstood: I think Cathe is beautiful either way, and I love that whichever we choose, we're strong and powerful)