This is only a small part of the huge Al Alam Palace complex. I imagine the balcony is used for public addresses to his subjects. This was taken through an outer gate to the premises.

Qaboos bin Said Al Said is the Sultan of Oman and its Dependencies. He rose to power after overthrowing his father, Said bin Taimur, in a palace coup in 1970. He is the 14th-generation descendant of the founder of the Al Bu Sa'idi dynasty. (Wikipedia)