When composing a picture we are told that we should have some idea of the outcome we seek, it's called visualisation. I have to admit that visualisation is not one of my strengths and though I have an idea of what I want, the framing of the picture is done with the camera. If I don't like what I see, I will change focal length, my position or both. The other variable is the orientation of the camera hence the title of the post. The naming convention gives a clue when we should use one or the other but these are not rules. Often rotating the camera will produce an unexpected result and it is often worth a try.
In this case both orientations produced a pleasing result but with a different feel. In the portrait version the converging lines of the glass bricks are more dramatic and the narrow space left on the left hand side gives the feeling of being squeezed.
The landscape version still has strong leading lines but with less drama. The space on the left hand side seems generous in comparison to the portrait version. Which is the better version? You make the call!