The Somnaran Sail was first discovered by Earth scientists when it entered the Orion Nebula. It was instantly classified as a threat, but soon showed that it's main purpose was to create and spread life throughout the galaxy.
The solar sail itself absorbs light through chloroplast cells embedded in the sails skin. This energy then spreads itself throughout the vessel using the complex vein-like structure until it has been distributed evenly.
The whole process was painted on my Twitch channel at Twitch.tv/finnpaints.