I totally suck at distinguishing between "ohhh, shiny, pretty!" and "that would look great on you". I figured that a visual aid would help find something that I really liked in its own right _and_ looked good when warn, especially with all the tahitian variation.
I did pick up a bunch of pearls that I thought looked great, and then looked meh next to the picture (the pearls were still stunning, just reserved for some other lucky recipient). So I'm glad I had the picture handy to guide me in the right direction.
This was the first time I'd tried this, but it won't be the last!