Most of mine are in landscape mode I'm sure. But a year ago, I used portrait mode every day for a month (just because the first few happened to be in portrait I think). It soon became a habit, and seemed to become a normality. So I think (at least for me), habits control what you do just as much as the scenery in front of you.
Your third image is a favourite by the way. The minimalism appeals to me, as well as the strong use of the available light.