Regarding your first link, the photo on the right -- the man does not have his false teeth in, nor is his hair combed. This, alone, will make a big difference in his appearance, just to be fair.

The top photo is what happens when you take out someone's false teeth. The bottom photos are what happens when you have drastic weight loss. My father never had dementia, but looked like the top photo when he took his teeth out. My mother did have dementia and looked essentially the same until she lost a lot of weight.

Just like my dad