I don't smile much on pictures. This has a simple explanation: The cam doesn't smile to me either. I don't see you people (and I'm not even sure if seeing you would make me smile or laugh or weep). Perhaps I should put up smiley faces on my monitor? I understand that I smile more when I'm with friends, though I rarely laugh (except an almost symbolic chuckle now and then).
On the other hand, I think I have a quite stable mood. I am not given to severe depression. This can partly be because I really don't have much to be depressed about. If I get some fatal disease, I guess I'll feel pretty low, or if I lose body parts. But not just because I love someone who doesn't love me back. Come on, there are 6 billion humans, what are the chances that you love the same person who loves you? That you even meet such a person? I'm quite satisfied to be allowed to have a few friends. And to the best of my knowledge, I no longer have any enemies. That's a rare thing in itself.
Yeah, I think fairly often about death, but I hate it intensely. That's not depression; that's ... hmm, existensialism. Yeah, that's it. Life is defined by its limits. And life is not only short, it's also very narrow. There are so many lives I cannot live. This is where friends come in handy. By merging our experiences, we can all become more whole, live more in the limited span we are alloted on this swirling marble, until our dust joins that of the dinosaurs and trilobites.
Some of my friends claim that eternal life would be a curse, that it would be boring. I thought so, too, when I was much younger than today. But now I find that it would be quite welcome, if it holds at least the same standard as the life I live today. I guess that's a pretty heavy indicator that I'm happy, whatever I look like.