Heh - I was kinda cheating too, since I remember that you have demonstrated a strong interest in photography before and own at least one DSLR. In addition being artistically inclined you probably shoot RAW often, and those files take up serious
space... like 15-25 Mbyes.
In comparison the average screencap is in the 300 Kbytes range and an iPhone picture (my primary camera) is typically around 4 Mbytes.
And actually I have most of my photos in Dropbox rather than the picture folder, since my phone is set to auto-upload them there whenever I get in wifi-range...