There is a bunch of videos on Youtube on Zipline, some of them from the company itself (this one showing specifically the "platform": https://www.youtube.com/watch?v=airEzThGlx8), and some from various tech people looking into the whole thing (like Markus Brownlee: https://www.youtube.com/watch?v=88yQTzlmsiA). Probably a better overall source of into than their website.
And it looks much safer than Amazon's approach of directly landing the heavy drone in your garden.