There are less general comments to make about the images every day, but there are some points still not mentioned yet.
Most of these images were made much before than the now common 16:9 format became the default size (I guess it’s the default now, at least for LCD screens, isn’t it?). UltraFractal’s default size when you just install it and opens the default image is a 400 x 300 px image (or was, at least), in the standard (and already old?) 4:3 format. It was the common size used for ages, with all these very known sizes like 320 x 240, 640 x 480, 800 x 600 and 1024 x 768.