Portrait Orientation
The frame pictured here represents a portrait frame with a narrower width than the height. This is indicated in the dimension, with the first number being the smaller number.
Example: 8 x 10.
Landscape Orientation
This frame, on the other hand, represents a landscape view. So the first number in its dimension would be the larger number because the horizontal measurement is wider than the height.
Example: 10 x 8.