How is the shadow of empty drinking glass different to full cup of tea mug?

The shadow of an empty drinking glass is typically sharper and more defined due to the glass's transparent nature, allowing light to pass through with minimal diffusion. In contrast, the shadow of a full cup of tea mug is often softer and more diffused because the liquid absorbs some light and creates a more opaque silhouette. Additionally, the curvature of the glass and the surface of the liquid can alter the shape and intensity of the shadows cast.