This is a picture of the American Megatrends Inc. series 735 Merlin motherboard. Or specifically, the clear plastic sheets of the solder pads artwork layer and other Printed Circuit Board (PCB) electrical layers. These plastic sheets or PCB films were used during the manufacturing process of the motherboard PCB to etch each layer of the PCB.
The Merlin was introduced in early 1996 and supported a single Intel Pentium® Pro processor, four 16-bit ISA slots and four PCI slots. It even had an onboard IDE/IO controller. Because it supported the Pentium Pro, it should have had a socket for CPU voltage regulator or VRM module but was instead incorporated into the board.
The Merlin was a Baby AT form factor motherboard. The Baby AT form factor was introduced in 1995 by Intel. It specified the dimensions of the PCB and provide a placement guideline for the various components. For example, the location of the processor, VRM, ISA, PCI, memory, keyboard port and other connectors.
In 2007, a cache of various PCB films were re-discovered in a closet. We had a few of the more art worthy ones framed. Many of the PCB films included the silk screen layer, which had text. The Merlin's PCB film did not. Ultimately, this led to the Merlin's PCB film to be framed backwards.
The problem was not noticed until 2017 and is still prominently displayed backwards in the corporate headquarters.