It shows the two sizes, 42 mm and 46 mm. In both cases the box contains the watch itself, with silicone straps already attached, plus the charging base and a cable. The first thing you need to do is to pair the watch with your phone, which as the video shows is an easy enough process.
The larger watch has an eSIM so it can handle calls and data away from your phone. On the 42 mm the eSIM is an option, there is also a Bluetooth-only version. You can see a side-by-side comparison near the end of the video.