In their beguiling third feature, “Donkey Princess,” León and Cociña split the difference between their first two, continuing their singular exploration of hybrid live-action cinema, but fruitfully returning to adult fairytale terrain. More downbeat in its whimsy, “Donkey Princess” centers on Princess Diana (“Hyperboreans” star Antonia Giesen), who doesn’t bear any resemblance to her famous British namesake, save for the fact that she’s suffocated by the demands of her very patriarchal kingdom. Tinted in queasy shades of turquoise and puce, it does not look like a world made to last, and for Diana, it isn’t. There, she and Lalo live together as parallel versions of themselves, also working alongside each other in the pest control business. “Donkey Princess” might lack “The Wolf House’s” intensity of vision and purpose, but it feels an intriguingly transitional work in an oeuvre that could go anywhere from here.