Isn't his chapter an allegory of buddhist teachings? Especially with the phone call in the beginning I certainly think so.
She was feeling tortured and tries to find a meaning for her life, something to live for.
She gets the camera and imagines the exhibition as something that can give her this meaning.
Therefore she experiences joy in the thought of finally finding a meaning.
When she finally experiences the exhibition, it is not as wonderful as she hoped it would be,
which puts her into a new cycle of despair.
So the whole thing only happened, because she is attached to the present world. Joy and Despair spring from the same attachment and for her to be free, she needs to rid herself of this attachment. To reach Nirvana.
That Siddharta himself wants to die certainly puts the whole concept into a nihilistic point, where Buddha was right that pain comes from earthly attachment, but Nirvana also isn't the solution to that.