Some sources give date as 1939.
Sporting white jodhpurs and a wild mane of hair, Carrington is perched on the edge of a chair in this curious, dreamlike scene, with her hand outstretched toward the prancing hyena and her back to the tailless rocking horse flying behind her.... Here, the white horse, which Carrington used as her symbolic surrogate, gallops freely into the verdant landscape beyond the curtained window. http://www.metmuseum.org/collection/the-collection-online/search/492697
female artistself portraithorsehyenarocking horse