Probably poorly judged. If they had used two kids, one coloured and one white they would have got away with it. Suspect it was some "right on, happening, agency that took the pictures without even thinking.
Context is important. Acknowledging the fact that all humans are apes & by extension monkeys (debate over terminology notwithstanding) in a dull scientific way is different from applying the term specifically to black people as a racial insult - which has a long history that people who work for the company responsible are unlikely to be ignorant of.
Anyone involved in marketing or advertising should be conscious of the possibility that something like this is begging to be construed as racist regardless of whether that was the original intent. Staggering incompetence on their part or were they conscious of the inevitability it would bother a great many people in one way or another?