Why couldn't I see the bee cocoon on the obs hive glass?

[twb]

My observation hive bees made some "sideways cells" on the glass.  In some cells we got to see larvae pupate and turn into honey bees with the eyes showing pigmentation first (fascinating).  But, why could we see the pupae when they spin a cocoon prior to pupation? I thought we'd not be able to see through the cocoon skin but I could not tell there was a cocoon at all.

[windfall]

No answer for you.

But I am excited to hear the bees will do this. Up to now they have only put honey on the comb burrcomb against the glass. I had hoped we might see some brood there as well but had assumed the queen was rejecting those cells.....maybe we will get to watch that too.