Ushnishavijaya is an emanation of Buddha Vairocana, who is invoked for longevity of life. The other two are White Tara and Buddha Amitayus. She is very popular among devotees in Nepal and Tibet. Ushnishavijaya shown seated in a multi-tiered stupa is a very popular image in the Kathmandu valley. According to textual sources, she is visualized seated within the dome of a stupa, indicating that she is the emanation of the mind of all enlightened beings and her most famous attribute is the small seated figure of Buddha Shakyamuni in her upper hand. She has a white colored body three faces and eight arms. The central face is white the right yellow the left is blue, slightly wrathful. Each face has three eyes.

The first right hand holds a crossed vajra at the heart. The second holds lotus on top of which sits Amitabha. The third holds an arrow. The fourth is in the gesture of supreme generosity.

The first left hand is in the threating mudra, holding a vajra noose. The second holds a bow. The third is in the gesture of giving refuge. The fourth is in the meditation gesture, holding a precious vase filled with nectar. She is flanked by bodhisattvas Avalokiteshvara to her right and Vajrapani, to her left. The four deities of the directions are assembled as: Achala (east), Takkiraja (south), Niladanda (west), and Mahabala (north).

Reference:

Sacred Art of Nepal, Min Bahadur Shakya, Handicraft Association of Nepal.