From Politico, right before the vote:

The Senate galleries are filled with spectators. Senators are starting to filter in and take their seats. Sen. Joe Lieberman is sitting on the floor next to Sen. Susan Collins on the Republican side of the aisle, listening to Mitch McConnell speaking.
The senators will vote from their seats, which is done only on big, historic votes. Sen. John McCain mocked the formality of a virtually preordained vote saying loudly with a laugh, “What’s going to happen?”