It should be covered in the EULA. Since the images are bundled with the software, they would all be governed by the same EULA in the absence of some separate licensing information for the images. If the EULA grants you permission to redistribute the images, all is well. In the absence of such language in the license agreement, I think you have to assume that the copyright holder holds the exclusive rights of reproduction, public distribution, and derivative work under section 106 of the Copyright Act. I'm sure there is some mention of it someplace in the documentation, though.