I once read that some 6x6 shooters see the square as more of a circle in terms of composition and framing. As soon as I thought of it that way, I stopped fixating on the waist level finder reversal. Once you imagine a bullseye in the center of the finder, it's easy to naturally center on the subject, then make adjustment for horizon or shifting the subject off center. The square means I never have to try shooting the TLR on its side for a vertical like an SLR, so it's easier to get used to the reversal than if you shoot 6x7 or 6x4.5 with a waist level. I originally masked my TLR for 6x4.5 to save on film, but it was so much easier when I switched to 6x6.