I've been following Nikki since she began back in like '03. Believe me this is nothing new. Her content goes in a formulaic wave (tame to basically topless) gradually transitioning over a 3-5 month period. Content always gets a little riskier through summer and there's always a big reveal around Christmas, New Years, Valentines, and Halloween. This way she keeps members excited every week to see what she may show, AND come the more revealing releases, signs up new ones who think just as you are now: She's finally gone topless!
I do have to say though, she has gotten far more brave, and naked, this past year.