Why does my phone say it has Denim but it doesn't?

Hi Wc, I am a windows 8.1 developer preview user with a lumia 520. recently i noticed that my phone is showing me in extras and info that i am having lumia denim. but i dont see any change in the phone as denim is supposed to be and main thing is that i don't remember doing an update for denim and i scanned for a phone update but my phone is showing me no update available..!!!! i am confused

For 520 latest pfd = denim. You won't recieve firware update, just OS one.
Untick pfd, restart your phone and than search for update,I think it shall find update but it will be the same as one youbare using now.