Up or Down
2 ways to tell. Either painstakingly work out sun angle relative to the view, complete with all the wobblies such as some images being arbitrarily 180 degrees rotated,
Or find one that also has a crater and use that for a sense-of-shape.
For what it's worth, I see the spider mounds as being raised above surrounding terrain, and the "branches" as being raised above the mounds (or laid on the surface, anyway - NOT raised in the air like real branches!).