LDD Can Look Better!
By default, LEGO Digital Designer renders in low-quality, but you can change it to render in high-quality if your machine supports it.
Advanced shading adds subtle diffused lighting and soft edge shadows which make pieces have more depth.
See The Difference
How To Enable Advanced Rendering in OSX
Step 1: Go to LEGO Digital Designer Preferences
Step 2: Check High-Quality Rendering Options And Raise Advanced Shading Level