Seeing Mt. Fuji is a very sporadic thing; I have gone through entire 8 day stays and never seen it, and sometimes I see it every morning (very rare after 10am, Tokyo haze or clouds take over). It's always a joy to see Mt. Fuji.
When it's visible, you also see it clearly as you are walking through the "library" between the reception area and Girandole. Once it was so clear and large in that window, I was stunned and my arms swung back, accidentally hitting two people walking behind me. One was a bellman, the other was Robin Williams. Interesting things can happen at this hotel, for sure.