This refers to when a person is wrapped up and restrained with bandages or similar bindings from their head/face/neck/shoulders to their ankles or feet, resembling a mummy, hence the name. This form of mummification is a more common usage of the term in art, especially in DeviantArt.
Generally does not involve the evisceration and embalming of the body, despite real world definition.
If a person is wrapped up like a mummy without their arms or legs bound/restrained, use mummification (non bound) instead.