We can see our face in a mirror. But why can't we see our face clearly in a aluminium or steel?
It's the roughness of the surface which matters. Usually aluminium and steel is machined in such a way, that its roughness reflects light in many directions. However, if you machine these materials such that they are "smooth" you obtain mirrors. This can be either done by machining the bulk material directly or by applying an aluminium coating to a "smooth" surface. You can buy aluminium mirror e.g. here.