Edit this existing image to add a third clear glass of water at the back of the wooden table, further away and slightly smaller to show depth/perspective. The image currently shows a cosy study scene with open books, notepads, pencils, and two glasses of water on the table. Keep everything else completely identical — all books, notepads, pencils, eyeglasses, the bookshelf, the chair with a blanket, the plant, and the warm window light must remain exactly as they are. The new third glass should sit naturally at the back/rear of the table. Photorealistic, warm lighting, not a cartoon or drawing.