"To the optimist, the glass is half full. To the pessimist, the glass is half empty. ..." (Unknown)

This is a piece of glass that caught my eye while I was on a tour of Estergon Kale (Castle) in Keçiören. At first I thought it there was a shadow behind the plate of glass obscuring the design, but it appears that it is a work in progress, half full of the design and half empty. I assume it is destined to become a window some day, if it ever gets finished.