No, I don't think that it will work because expressing that way dispalys the image in proportion to the text. If the text looks smaller at a different resolution so will the image.
It is a very difficult problem: one of the sites I've done for work looked a bit boring so I stuck in some recently discovered photos of bits of the library that no-one can see anymore. First a colleague in my office complained that the image took up far too much space (she uses 800x600) then someone else came in and complained that it looked lost because it was so small (1280x1024)
Yes it is a part of a work in progress project that will need a way of fixing that feature to a page size for the project to work No good having a page with tres either side and stars in a night sky in the center then find on a different size monitor that the stars are in the trees ;)
Maybe there is a different formula for adding the stars;)