If, as you've indicated, you haven't printed it yet, you might consider cropping it to a less square aspect ratio. In that respect, a more favorable composition might include getting rid of the bottom 20% of the picture, while keeping your "holga vignetting" at the top, for a 4:5. That would solve your problem, allowing it to repose more naturally in a classic landscape orientation for framing.
Originally Posted by bvy
I do indeed agree with your sentiments about "too square". The show requirement that matting be conservative is telling, in an Eggleston kind of way, and from my perspective that sort of huge frame / small picture style certainly does take the edge off the square. I so rarely come across compositions that absolutely favor equal dimensions, that when I do, I will force them to other aspect ratios as a pragmatic presentation choice (see Cropping a Negative). It's your canvas, your art, your choice.