I started this one in December for the CCC, but didn't finish it until April, because I was busy with many things. It was interesting experimenting with a hexagonal structure, and limiting the palette to white and clear bricks, but the funnest part was messing around with the lighting. I used a blue finger strap-on light, which I fixed inside the tower and hid with the camera angle.
Playing with light through LEGO -- tons of fun! In the dark, basically a LEGO light show you've made, and a fine one at that! Love the 3D object defined by the light itself. I play with light mostly through spinning tops and Technic gizmos designed to put on blacklight shows. Now I'm going to have to try some static light displays like yours.