Vibhuti is the sacred ash associated with Shiva and every now and then at the end of an abishekam it is sprinkled over either Ganesha or a Shivalingam. Note that the priests have carefully cleared away Ganesha’s eyes, so that he can “see”. Notice that they have also added a dot of red kumkum on his forehead. Next in the abishekam process they will offer a couple of pieces of fruit and burn some camphor while chanting a few mantras. Then the vibhuti will be rinsed off.
One of the reasons that I love this photo is that it looks like Ganesha is covered in snow.