It's common knowledge that the worst part of most customer facing roles is the customers. There are plenty of nice, decent people out there, but they are sadly outshone by the minority of complete a-holes who are hellbent on ruining the shift of a minimum wage worker.
The skill of socializing with the general public is a tricky and ever changing thing that many in these jobs would be happy to avoid. These individuals are in luck, because apparently some rich newlyweds have found a way of using hospitality employees that erases the need to interact with them.
The 'champagne wall' is a wall made to look like a hedge. Wedding guests ring a bell attached to it, and a hand reaches out from a gap and hands them a glass of champagne.
When the video first hit Twitter, people were critical of the way that the concept took the humanity away from those working the bar. However, plenty more insisted that not having to deal with face to face interaction was a huge relief. Maybe the real issue here is that the whole thing is kind of tacky.