Alright, I'll try for a more extended description of why I also think this is a strong image.
For me, a lot of what I'm looking for in an image is some sort of emotional impact or connection with/through the image upon viewing it. I am also interested in the image holding my attention for more than an instant. Images that are visually stunning often don't have the ability to be engaging for a longer period. I find that Timo's image, here, succeeds on both of these fronts. I've been back to this page several times and viewed/experienced this image for almost all of Minor White's suggested 30 minutes and I still find the image provocative and engaging. I would happily live with it longer.
Timo's photograph manages to express so much about winter with so few elements. The frost and ice clinging to the branches of the tree and outlining its form make for visually stimulating components of the image. Due to the minimal number of elements in the composition and the gloriously clean background, I find that I can really let my eyes rest upon the ice-coated tree and absorb the intricacy of the details there. However, I find that what is really important is how clearly the fragile and usually fleeting display of the ice expresses the delicate beauty of winter. The clean purity of the blanket of snow conveys so much about the power of winter. The silence of a snow-covered landscape can almost be heard (or, rather, not heard) through Timo's image. I also find here, a reference to the power of snow to isolate and to subdue. I feel Timo has expressed this less joyous side of nature through his choice to keep the contrasts low and keeping this slightly underexposed. This allows the sky to feel somewhat heavy and closed in. The toning he has applied works well to accentuate these elements of the composition.
Part of what makes this image so successful for me is that it achieves all of this with such a minimalist composition. It is fully engaging despite having such a paucity of elements. Clearly, it has just enough subtle detail to remain compelling for long periods. The variations of tone in the foreground snow strike me as especially nicely maintained. Moreover, I think many underestimate how difficult it is to find such clean, minimal scenes. Despite loving this sort of compositional structure and always looking for it, I find it is hard to locate such clean horizon lines and isolated elements. I often imagine it would be easier in a less flat landscape (I'm in southern Ontario) where rolling hills (or more) would give you the ability to get down below your subjects and isolate them more easily. However, that is merely a supposition.
I will now join a number of the other posters and say that there really is simply an issue of taste here. Either you like and enjoy minimal compositions with sparse elements or you do not. Do you like Beethoven or Arvo Pärt? Mahler or Satie? Monet or Mondrian? Klimt or Klee? Rubens or Rothko? Ansel Adams or Sugimoto?
If you feel interested in exploring similar work, I might suggest some of the work of Michael Kenna. His most recent work from Hokkaido comes to mind looking at Timo's image here. Even his earlier Hokkaido portfolio is worth a look too. You could also check out Josef Hofflehner's portfolio; especially his snowscapes. There are plenty of other names I could suggest, but looking at those portfolios would be a good grounding in a similar style. I think Timo's image here achieves much of the best of those other examples.
Imo the difference between a good photographer and a really good one is imagination? I possibly lack some imagination! However after reading this I think you have applied too much imagination when you looked at this image? Imo you are seeing things that most photographers would not? I have never looked at an image for anything like thirty minutes.