Someone recently posted a suggestion that AB should have a philosophy section. If there was one, I'm sure your question would belong there, rather than here ;-)
As a graduate mathematician, heavily into nihilism, my representation of 'everything' would be a simple circle, drawn onto a white background. A circle is 'all encompassing' because, for any given perimeter, it has a greater area than any other closed loop. Also, because it appears on a white background, there's nothing outside it which isn't already inside it. (i.e. any white point outside the circle has a similar white point inside it).
Chris
PS: I've got two questions about your image of 'everything':
1. Why is the silhouetted figure female? Surely an asexual figure would be more 'all encompassing'?
2. Doesn't your picture leave the silhouetted figure as external to 'everything'? If so, 'everything' is incomplete because it doesn't include the figure itself.