Sorry, I forgot to reply here... An attempt of an explanation: The snow picture is kind of the center of this small set for me. The first picture corresponds in a graphic way, the shape of the earth covered by the snow reminds me of the foliage "covering" the sky or vice versa. The colours in the third picture are very monochrome and bright, and in a way it's also about things covering other things, so this is my connection to the snow picture. And yes there are bottom left to top right diagonals in all three pictures. I am aware though these connections are probably quite far-fetched and I might be the only one to "get" them. ;-)