Known as 'the Paine Miniature'.

Lee Porritt has written about this miniature in The Paine Miniature – Is it Elizabeth? at https://ladyjanegreyrevisited.com/2021/05/12/the-paine-miniature-is-it-elizabeth/:

"A Memento Mori or skull is depicted on right-hand side of the miniature with the wording: AHI MORTE TU TOGLI & NUNQUA RENDI TU PRESTI & MAINON PAGHI placed vertically along the side of the sitter.

‘Remember you have to die’, is the rough translation for the Latin word Memento Mori. The symbolic use of the skull, rotten fruit or sometimes a butterfly have been used throughout history to remind viewers that death is inevitable. These symbols became popular in the first half of the sixteenth century and were used in portraiture, jewellery, and illustrations. Today, the image of a skull reminds the modern viewer of danger or a rather morbid obsession with death. However, in the sixteenth century the image of a skull was used as a polite reminder to live life to the full and that death unites everyone as it is the one thing human beings are guaranteed in life.

The inscription [...] appears to be Italian, and roughly translated to ‘Alas death you take away & you never lend & you never pay’, which is again another reminder to the viewer that death will come someday."