The giant waves seem a little underwhelming in this image. If you are not paying close attention you might confuse them with the mountains they are engulfing. But this problem aside I actually quite like the idea of the poster, and of the related scene we can see in the trailer.
The basic formula for making a disaster movie poster is to show some important landmark being destroyed. Like I said before, this might not be very original, but it still seems to work.
However that doesn’t mean it’s not wise to also try something a little different. Here we get the same premise, but instead of some recognizable landmark we get a mostly anonymous landscape. However, we have the solitary monk, standing there, unable to do anything but await his demise. This adds a certain flavor to the whole thing and, more importantly, adds a human element that is often missing from the mostly sterile posters for the genre.