What is a gallery?

A gallery is where you can put items in to pretty much show of to subeta.:)

So how do I make one. I am trying for the hoarder achievement.

Make a shop then go to Edit Shop and change it from Normal to Gallery.

First you make a regular shop,then click edit shop,and theres a drop list that says shop type where you can choose it to be a shop or gallery.

OK thank you very much.