This is stupid. If that guy wears a white shirt, I am sure you could see red droplets on his shirt as when you pour wine from a height, the wine is bound to splash when the stream hits the decanter.
Note also the way he held the decanter, he was going to warm up the wine by about a degree or 2 Celsius, thus ruining the wine.
Do not attempt this at home; only performed by professionals ( in their own mind) who mix shark fin soup with rice, and Lafite with 7up.
Even if you use a decanter with a bigger mouth, the wine still splashes as this is what liquid does when being dropped from a height. It might not SPILL out as much from the decanter with a bigger mouth, but small droplets are bound to be flying around and you bruise the wine, especially if this is an aged wine.
Professional sommeliers do swirl the wine in the decanter to give the wine more contact with air; but they do not slosh or splash the wine around inside to bruise it.
Learn form someone who has drunk wine for more than 30 years, Smartie.