Because you enjoy juxtaposition with your espresso.
I know I do.
Love the faceted, hard exterior and the lovely motif on the inside that will slowly reveal itself as you drink. Oh, Scandinavians; you know how to design some shit.
Demitasse cups at the Finnish Design Shop.
Thursday Night Smackdown 
Ooh, I want those. I would probably use them for tea rather than espresso, but they are absolutely beautiful.
I love unique espresso cups! I’d need 4 so I’ll have to save up….