Here is mine, which as my proposal says "humorously illustrates the school motto, 'Fiat Lux/Let There Be Light' with the school mascot, a banana slug. Though the motto and mascot both represent the spirit of UC Santa Cruz, they were adopted at different times and so, taken literally, they are in opposition." It is very convenient that our mascot is one of our school colors, I took it for granted while I was working but not every school has that.
If I'm selected I'll paint the whole box blue with the slug image on the front and on the side it will say Fiat Lux and under that Let There Be Light. I was really keen on leaving off the English, but my professor was very clear that no one can be expected to know Latin and I should use both. I was horrified because this is university. So really, I was saying "fiat lux" in a this-is-a-university-have-some-freaking-knowledge way and she was saying "fiat lux" in a language-is-not-for-obscuring-messages way, and hers was less classist so I backed down. However she also suggested I "put a note on the back explaining that slugs like darkness," to make it clearer, which I did not do.
I didn't think I wanted to win but now of course it's out of my hands and I do. But there were loads of beautiful proposals so I doubt it.