Here is my photo of our yawning cat redone as a light stick image (no diffusion sheet over the LEDs).
Technicals: LED Light Stick image cropped: 56 mm, ISO 200, +6 stop neutral density filter, F4.5, 10 seconds.
The image used in the light stick had .49 gamma color adjustment and resized to 80 x 64. The camera was on a tripod as I moved the stick, in a upward, downward, upward pattern. Moving the stick this way made the image more 3D like.
Here is a another version using a light diffusing film over the LEDs (without using a neutral density filter)::
