Look at the shape of the ears.
That is one characteristic that is used to ID people.
While I do agree w you about the ears, it’s a losing proposition to argue about it. Studying one or two infant/childhood images on the Net is no way to identify an adult. Sometimes people look at actual photos of the adult in question, & still can’t identify him (or even get his gender correct—much less whether he’s dead or alive).
The way to get to the bottom of the David question is to interview people who knew the Ndesandjos when the boys were growing up. The local newspapers can be consulted also. If David were a fictitious entity, someone would have blown the whistle by now. Instead, crickets. As contrasted by mentions of him in both of the region’s largest papers, as well as by those who actually interviewed friends & neighbors.