When printing on brushed aluminium there will be no white ink on the image. It will be the silver natural material that will replace any white areas. This is due to the fact that there no white ink. When you see pure white in a photograph, you are actually seeing the paper. Additionally, due to the 'brushed' nature, the aluminum panel will have texture that adds depth and radiation of light to the image.
This medium is most complementary in architectural images displayed in well lit areas.