This is the innermost part of the coffin set of a woman called Henettawy, who was a Chantress of Amun-Ra during the late 21st Dynasty (so about 3000 years ago in the Third Intermediate Period). It’s her mummy board, which sat on top of her mummy inside the inner coffin.

I took this photo of the lower half of it because I found the decoration quite striking particularly in juxtaposition with her other two coffins. They are elaborately decorated with gods etc, as is the top of the mummy board, but the bottom is simple, restrained and elegant.

The red background is represents a red cloth wrapping around the mummy, and over it is depicted a bead net dress. A couple of such dresses have survived (and been restrung), one of which is in the Petrie Museum (see https://www.ucl.ac.uk/culture/petrie-museum/bead-net-dress).

It is now in the Met Museum, acc. no.: 25.3.184.

See it on my photo site: https://photos.talesfromthetwolands.org/picture.php?/1546/

I also have a photo of all three parts of the set: https://photos.talesfromthetwolands.org/picture.php?/1551/ and if you go right there are several more photos of the coffins.

Jigsaw Puzzles:
easier: https://www.jigsawplanet.com/?rc=play&pid=1fb3a9efb745
harder: https://www.jigsawplanet.com/?rc=play&pid=1f7ba5be09de