I know you've made your decision, so I'm just saying this for analysis of your next purchase (I DO hope you find *your* camel pants soon! These outfits are fab, especially that last one --- to die for!)...
I think the reason you feel/look different (not smaller, not bigger, but *different*) is that (a) the fabric is more snug (they are jeans, even if they aren't skinnies, so they do the hugging thing around the hip and butt, you know?) and (b) the fabric is matte and textured by virtue of the way denim is woven vs these, which reflect light more due to the smoothness. I think the effect will always be visible 'only on camera' rather than in real life. I recall a pair of navy wide legs I had that always looked frightening in photos, vs my jeans, largely due to the slightly shimmery thread woven into them --- but I got compliments on them in real life all the time. So I don't think it's the colour; it's the texture and how it translate to photographs.
If this were eveningwear you were buying, I'd think harder about how they translate in photos. But since it's not, I think it is more important to go with the RL impression, you know?
FWIW, I really like the fit of pants that fall straight from the hip --- on myself, at least, so maybe that influences me here. I can see the more snug-to-the-thigh fit looking sleeker in comparison, like Una said, but I also find that more unforgiving visually and less comfy to move in physically. To me, that freedom of movement is critical, and I'll only do snug-to-the-thigh in a lighter weight fabric with stretch. And again, you usually can't tell weight/drape from a static photo, but it does look different in real life.