The properties would include the size, position, colour, label, etc, covering all image object properties.
Such effects are achievable with the relevant programming language of the office suite (e.g. VBA, OpenOffice Basic, LibreOffice Basic, etc), however such functionality is not easily accessible to the average user.
Making image objects formula-driven should be fairly easy within the existing interface, i.e. where the user normally goes to edit an object's properties, they can put a formula (with cells references, functions, operators, etc) instead of just a value. The below image illustrates.
It would also be useful to have dedicated "image" tabs to the spreadsheet program (similar to chart tabs).
Formula-driven image object functionality should extend to other elements of the office suite, e.g. for the word processor, presentation tool, etc.
Why would such a tool be useful? To allow the preparation of dynamic diagrams that can change as the user's data changes, and can be easily updated. For example, non-chart ways of presenting numeric information.