Statuette of a Male Deity
Gneiss, 8 3/8 x 3 5/8 in. (21.3 x 9.2 cm)
Egypt, Old Kingdom, ca. 2675-2625 B.C.E.
Brooklyn #58.192, Charles Edwin Wilbour Fund
Photo © Joan Lansberry, May 2008

(From the info card)
"The figure's large wig and unusual clothing, which consists of a penis sheath attached to a belt, indicate that he is a deity, but his exact identity is uncertain. Made for either a temple or a king's tomb, this statue was the product of a royal workshop, where very hard stone such as gneiss was finely and carefully modeled. This depiction of the god's strong, youthful body reflects the ideal of the male form in early Old Kingdom sculpture."

Why does the statue appear bluish in my photo, and gray in the museums's photos?

Photo at far right is raw from the camera, without editing.
COLOR in CONTEXT, in situ, he is reflecting the blue in his environment!