Not sure if it is possible to 'pass' images. You can pass a path, which later you will have to use to load the image with ActionScript (for example mc.loadMovie( path )). Remember, that flash does not accept all formats this way - only jpeg (no progressive jpeg, gif, bmp, png...) - unless something changed in the latest versions...
BTW. This is a flash question - you would be much better off looking at some flash-dedicated sites...
Piotrek is right, yo cannot "pass" images itself, but their paths. to do so in eZ you have to grab the url of the image.
in your case this would be something like this:
{$node.data_map.Image.original.url}
original is a so called image-alias, of course you could create an custom image-alias yourself (to resize and/or crop the image) and use this alias instead.
{$node.data_map.Image.content.flash_image.url}
In this example flash_image is your image-alias that you have to define in image.ini.append.php before.
Yup, you may even decide whether to do the logic in the eZ templates and only pass prev/next URLs to Flash (this would be my choice) or pass "the ingredients" and calculate using ActionScript. This is not eZ Publish issue - look for "passing variables to flash" online.