Why do you think people are "getting offended on behalf of someone else"? I think H and M made an obvious cock up and the photo was inappropriate, for the reasons that have been well explained by other people. I've no idea if there was deliberate intent by someone or if everyone involved just failed to spot the problem.
I don't know why. As i said, i find it very odd. I don't see an obvious cock up or problem . If i really tried i could maybe muster up a modicum of offence on behalf of others, but i'd be being awkward just for the sake of it...
The shirt colour is a bit too 'republican green' and might cause offence or even outrage to some who live in my area. Im sure i could persuade be the local Orange Lodge to get behind me on that one.
Coolest monkey in the jungle? Jungles are warm so no need for a hoodie. Offended by unnecessary clothing? Are you with me nudists?
Or evolution suggest humans share an ancestry with apes. Apes/monkeys what's the difference? (no need to answer that). If i was religious i could be offended by that as i'd believe God created man. Pretty sure i could get a good crowd to pray for the editor (or stone him)
You can pretty much find offence in anything if you try.
Quick anecdote. I once designed a logo for a local computer company. Based on the old emerald green/gold circuit boards incorporating the initials of the company's name. I deliberately changed the colours so as not to incite the hatred of the local prods (no offence prods!) and the finished job looked pretty good. Customer was very happy and promptly paid. A few weeks later i got a call from the client asking me to change the logo. When i asked why he informed me a customer had told him the logo looked like a man shagging a boy from behind! Client couldn't see it and neither did i but i changed it anyway (to a boy shagging a man
To me it said more about the person who saw the filthy logo that it did about reality. That may or may not be the point.