a (postage) stamp，特別是和信封比起來，是小小的一張紙，進而衍生出這種用來形容很小的一棟建物、一塊地等等的說法: a postage stamp of a building/land/lot/…
https://patch.com/rhode-island/providence/rhode-island-diner-named-among-12-best-new-restaurants-u-s
“There, There, in a postage stamp of a building that was once home to a beloved hole-in-the-wall diner in the city’s West End,” Adams wrote.
There, There 是一間小餐館的名字，位於 Providence, Rhode Island, USA
https://maps.app.goo.gl/6qd4MMBbY7KUDkQW9
hole-in-the-wall / hole in the wall 也是用於形容一間小店
https://haowon.freeflarum.com/d/261-hole-in-the-wall
