The representation of Buddha with flames rising from his shoulder refers to Sravasti, where Buddha performed eight miracles to demonstrate his superiority over the Kasyapas. During the dramatic first miracle, flames issued from his shoulders and water streamed from his feet.
Compare with a closely related standing figure of Buddha flanked by two smaller depictions of seated Buddhas, each with flames emerging from their shoulders, at the Musée Guimet, from Paitava near the ancient capital of Kapisa, see D. Klimburg-Salter, Buddha in Indien, Die frühindische Skulptur von König Asoka bis zur Guptazeit, 1995, cat. no. 176, p. 279f. This iconographic type has precursors in the ancient symbolism of light and fire, as well as the Hindu god of fire, Agni, as a cosmic principle. More specifically, it relates to the Indian conception of the 'Universal Monarch', with similar depictions of Kushana kings on coins, where the royal flaming shoulders are symbolic of the majesty of a great monarch and of his fiery energy and superhuman power, see J. Rosenfield, The Dynastic Arts of the Kushans, 1967, p. 200, and W. Zwalf, A Catalogue of the Gandhara Sculpture in the British Museum, 1996, p. 31. While this specific motif is later abandoned, it sublimates into the flaming halo ubiquitous in Buddhist iconography. The formalized linear treatment and pronounced folds of the drapery reflects the culmination of Gandharan art leading into Central Asia.