They thin out like that when they are on the move and scared. I took those pictures within 15 minutes of getting him in his new home. That is totally normal, when he is hanging out on a vine, he is nice and plump! He eats like a horse, but because of Metabolic Bone Disease, you have to feed them carefully when they are young (Up to 6 months) because they will grow too fast for their bones to catch up. He is allowed 10 crickets ( which he gobbles in up very quickly) a day broken up into 2 feedings and they are dusted, depending on the day, with 1 of 3 things. Calcium with D3, regular Calcium or Herptivite vitamins. They don't drink from water bowls, they need a drip and/or a misting system. And yes, he is drinking well!
We had a HUGE male, our first in 1997, and he wasn't handled when he was young by his previous owner and he was quite intimidating. He lived to be 6 years old and passed away. We then got a male and female in 1999, handled them once day and they were fine. The female was egg bound and passed away at 2 years old and we had the male for 5 years! Chameleons are kind of sit back and watch pets rather than hold and play with pets.
Veileds are a great starter chameleon along with panthers and Pygmies. Pygmies require a different set up, they do well in a terrarium, other species are arboreal and need height and vegetation. You should never keep more than 1 of any species in the same enclosure with the exception of the Pygmies. They can be kept in pairs or trios.