The main shape of asteroid is based on astronomical datas. Surface features are my "artistic" concepts.
From wiki:
Daphne (minor planet designation: 41 Daphne) is a large asteroid from the asteroid belt. It is a dark-surfaced body 174 km in diameter is probably composed of primitive carbonaceous chondrites. The spectra of the asteroid displays evidence of aqueous alteration. It was discovered by H. Goldschmidt on May 22, 1856, and named after Daphne, the nymph in Greek mythology who was turned into a laurel tree.