Small image in large matte is twofold: fits the theme of the show and is a cost consideration as well. But can you expound on the your statement? I would be interested.
It's just a personal view. I've seen lots of tiny images, surrounded by acres of white mat, in large black frames. It's always seemed to me both pointless and in some way pretentious, and something in me balks at the idea of paying a premium for a big sheet of cardboard and a larger-than-necessary piece of glazing material.
So, I wouldn't buy anything framed in that way. Others may differ - and no doubt do.