The triangular object on f76v

[bi3mw]

What could it be and why would it be above this nymph? I've likened it to certain things before but I'm unable to fully understand its significance. What do you think?

I like your idea of "invisible stairs". I think the nymph on f76v  has her head in the clouds . Let's say my reference line is the "exosphere" . Depending on this lines position, the nymphs are placed whithin the sphere ( if existing, otherwise below ). My drawing skills are limited, but figuratively the whole thing could look like this :