Lady Armatrude Waechter de Grimston originally commissioned the toilet set from which this mirror comes. It is one of the biggest and most successful commissions in shagreen. (Shagreen was originally a species of untanned leather, but from about 1750 nurse sharkskin or the less expensive dogfish skin was used.) The chased decoration of the service has an aquatic theme. It recalls Cooper's description of shagreen:

'a material possessing some of the qualities of both mother of pearl and leather. Its little nodules of concentric rings give one, when the skin is particularly translucent, the feeling of looking deep down into a pool of sea green water . . . One can't do much with a thing like that - put a silver bank round it, I mean a silver moulding, that is practically all.'

Marine imagery clearly stirred Cooper's imagination. On the mounts he represented the shagreen's murky depths - fish, lobsters, crabs, shells and seaweed. He had made preparatory studies for the designs during a family holiday in Sheringham, Norfolk, in 1927.
Chased representational mouldings are extremely rare on Cooper's shagreen. They appear only on a few pieces executed between 1924 and 1933, and then mainly on feminine, toilet articles.