Which function makes pictures open in floating window?

Hi, Just wanted to ask, which of the functions makes the pictures to open in this floating window, I would like to edit this function and remove some text from it, see attached image, as I am not sure I can explain what I mean exactly by words:)

In red ring is part that I need to remove completely
http://imageshack.us/photo/my-images/821/galeryd.jpg/

Thanks for any help in this matter