...as soon as I looked at the image. Unfortunately I can't answer your question.

If it was made by Nephila clavipes... what is it? The egg sac is usually attached to something.... like a tree branch/trunk. Do you guys think this is wrapped food?

I wonder if this could be a silk moth cocoon that somehow got tangled in a Nephila web? Maybe the branch that carried the web fell onto a branch that was carrying the cocoon causing the cocoon to detach and get tangled up. I don't know how possible that is, but it's a hypothesis at least. :)

Hyalophora cocoons...

not a cocoon because of the way its corners are drawn out, clearly deliberatey placed there by the spider; and not wrapped prey because of the "decorative" black silk mixed in--I don't know of any spider that would use anything other than plain white silk to wrap its prey (or that would draw out the corners of the prey's wrapping like this). It doesn't seem to be a Nephila egg sac, based on this; I think Nephila is the only spider that would produce golden silk in its web, but lots of spiders produce colorful silk when making their egg sacs. The first thing I thought of when I saw this photo was

...I don't have any personal experience with that species, but I think the egg sac is not always that color. It would be interesting to get Jeff Hollenbeck's opinion... would be nice to know how big this was too.