I have seen pics of cakes where the icing is shiny....how is this done?

What kind of icing? Most of the time it is fondant and there are a couple of way to make it shiny.
ONe is to paint it w/water - just lightly. Some people use a cloths steamer but I hear that only lasts a short time.
If it is b'cream - well that usually is a bit on the shiny side already. You can add luster dusts to bring out a bit more shine. (To fondant too.)