A sign-maker might call describe an “Illumination” as a double-sided light-box using LED light strips to edge-light an acrylic sheet and to illuminate back-lit print media.
What that means is that there are strips of high intensity, low wattage LED lights mounted in the frames. These strips abut the edges of the acrylic sheet that the frame is holding. The acrylic transmits the light through its surface. Adhered to this surface is an inkjet print of the painting that has been made on media specially manufactured for backlighting. This media picks up the light from the surface of the Acrylic and radiates it outward.
It is a simple effect, but it is dependent on an array of sophisticated technologies: LED light, Acrylic Sheeting, Inkjet Printing, Synthetic Fabric.