Centred Composition and Symmetry
The most important feature of any photo narrative is the subject. In this case, the oak tree – being placed centrally – is clearly the main subject here.
And perhaps the most obvious compositional feature that lends its weight to defining the subject is the leading lines: (1) the top line of the fence on the left, (2) the foreground rocks running from the bottom left corner to the base of the tree, (3) hill horizon on the right, and (4) the top line of the distant hills.
These serve to draw the eye through the image into the centre.