In short and simple terms, "double snaps" means a lot of appreciation or agreement for something. It's like giving two thumbs up or clapping twice to show that you really like or approve of it.
Sentences with «double snaps»
I always like double snaps on covers as the fit seems better. (diaperjunction.com)
Double snap closure for a comfortable stable fit No need for a cover! (happybeehinds.com)
Convertible handles allow for multiple hanging options with the use of double snaps. (diaperjunction.com)