This place is a JEWEL of Art Nouveau.
Passage Pommeray is a place that sets some shops. Passage in english could be translated as "path" but its more than that.
Sure, it links to streets: rue Crébillon (one of the biggest shopping street) and another one (whose name I dont remember). But its a big path with stairs and many shops.
Its art deco style, that is beginning of XXth century and has a very rich architecture inside.
It will take you only a few minutes to stay there but it will make you go to another world.