Horizontal, is the new portrait orientation.

uke:

uke:
Dizactly.
Horizontal on a shot like this is the kiss of death: it creates a floating head with two large patches of empty space on either side of it...horizontal makes sense ONLY if there is an environment or a background WORTHY of using a horizontal framing. Using a horizontal framing on a head and shoulders shot eliminates the SHOULDERS. Using horizontal on a bust shot eliminates the "bust" or chest, and ruins the pose! Using a horizontal framing on a head and shoulders shot REDUCES THE SIZE OF THE HEAD AND FACE, tremendously, and INCREASES the size of the dead, empty space.
There are many,many valid reasons why professionally trained, classic portraits have been done in the vertical orientation, dating back to the 1400's. Anybody who has studied formal portraiture, or who has studied composition or design, will understand the how,what,and why of using the compositional space to its best advantage. When I see horizontal framing on headshots, head and shoulder shots, bust shots, or half-body shots of a single portrait sitter, and there is not a truly interesting background that is WORTHY of inclusion, I know that the person who mashed the shutter button is self-taught, or untrained, and has not studied or been taught by anybody worthy of being called a mentor.