retow, my reactions are that your second has much more punch - depth of color, richness and the lighting is much better and hence, to me, the picture has more power. As for guessing about cameras or lenses - I wouldn't have a clue! Your first photo has a more pensive quality but to my eyes, on my computer monitor, it seems a bit washed out. Though the second is more of a snapshot and is pretty humorous - it "looks" better to me...whereas your first seems a more thoughtful portrait, but seems to need a little "tweaking" - all is just my opinion. Not sure if this is what you were after or not, retow.
Like BB, I prefer the second. It's much more contrasty and the light is nicer. The first looks quite pale and the background is a bit distracting for a portrait. Couldn't even begin to guess which camera/s these came from however! I also think that the pics are posted a bit too small to be able to judge lens performance. I really like the second. It's a good catch so you must have used a fast shutter speed Probably need input from people more knowledgable than me.
retow, I've moved your post and the comments into the Photo Critique forum, rather than having them stay in the "Words/No Words: color portraits or photographs of people" thread because eventually someone would have come along and added another picture and your photos and questions would have gotten lost. The Words/No Words threads are a better for posting images and if one get's feedback that's great but it's difficult to have any sort of real ongoing discussion due to their nature.
Thanks for your input, and yes it is a small sensor camera. The sun was out when I shot the second one, whereas the light was dull and greyish with low contrasts for the first one. Flash was used for both. I think the tiny Pentax Q did a decent job in both by reproducing what my eyes were seing.