While I don't always respond to every comment, I do read them all and appreciate them. I pretty much only reply when I feel like I actually have something worthwhile to say. So if your comment sits there getting lonely, assume it's because I couldn't think of anything better to say than something inane and pointless.
Also, I tend to silently make edits and little corrections to my pictures, at least those from vectors. So if you catch one of my uploads very quickly after I submit it, chances are it'll be a little different later on. I try to have the picture fully completed before I upload, but it just often turns out that I notice some little problem after the fact. And on that note, if you spot anything that looks like an error, feel free to point it out so I can fix it.