Getting to the right keywords....
... sometimes takes some time and a willingness to look at the search problem differently. Let me tell you my story of searching for this thing. Our original Challenge was:
1. What does one call the hanging thing in the above image? The topmost ring about 6 feet across (2 meters) while the bottom ring is about 3 feet (1 meter) in diameter.
I started with the obvious Search-By-Image, but as you can see, both Google and Bing's search-by-image functions fail pretty spectacularly. And you can see why--the background is also pretty striking. It's difficult for humans to separate foreground from background here, so it's not a surprise that Google would think this was a peace sign...
I had to use "traditional" keyword search. But where do you start?
Since this was seen in Rome, I started with regular web searches like:
[ Italian hanging wreath ]
[ Rome two rings ceiling ]
etc etc. I won't bore you with all of the searches I did, most of which didn't work out well.
I changed my strategy to do more visual search, using Google Image search with those same queries.
It wasn't working out well. So I asked myself, "How would I ask another person about this?" When I described the search Challenge to a friend, I realized that the word "chandelier" would be useful. (It was literally one of the first words out of my mouth, but oddly, NOT one of the first search terms I thought of!)
An image search for:
[ two ring chandelier ]
which worked much better, giving me something to work from.
These results are pretty good, but missing the greenery / foliage part of the original image. A quick modification of the query to include "greenery" and "tent" gives results this, which are much better:
These are getting pretty close to our original image. A bit of hunting around in these images told me lot about what these things are, and where you can buy (or more likely) rent them, because, honestly, do you have space for one of these in your backyard? I don't! But they're great in larger public spaces.
To answer our other questions:
If you went into a store, what would you ask for? Answer: A "ring greenery chandelier" or "foliage" or "floral."
What kind of store would you visit to buy this... thing? Answer: Either a place that rents party gear (e.g. tents for weddings), or just a wedding store!
I really didn't expect this answer, but now I know... should I ever be in the market for giant hanging chandeliers of greenery (or flowers)!