People are sharing screenshots in word documents. Therefore I share pictures as excel shit.
It turns out that someone had that idea already: http://think-maths.co.uk/spreadsheet (thanks sphereinabox)
And someone else too: https://github.com/milkey-mouse/excelify (thanks Milkey mouse)
The project page is on github: https://github.com/bjonnh/xlspic it is also a good demonstration of how to play with parsing images and excel files in Python using Xlsxwriter and imageio
Also it was covered by Hack a day: Images as excel files are gloriously nasty (2018).