Sony wanted to show off how thin and light the new Xperia Z4 Android tablet is compared to the previous generation. They decided it would be fun to send their new tablet floating through the air with some helium filled balloons. They reiterate that their device is 6.1 millimeters thin, which is .3 millimeters thinner than the 6.4 millimeters of the previous generation. They also tout the tablets new svelte weight of only 389 grams, which is 50 grams lighter than the Z2 Tablet.
I'm not sure they thought this whole thing through all the way, because they could have also been inadvertently showing off how well this device handles being smashed to the ground from higher than anyone would likely drop it. Luckily everything turned out okay.