In 2004 the German company Heckler & Koch’s product catalog was released at an industry trade show. Unfortunately their photographer didn’t notice that their cartridges had been loaded backwards into the magazine.
This sparked a meme of sorts among HK enthusiasts where they would mimic the error stating that was infact the correct way for HK pistols.
Here’s two examples:
Wide part of the magazine, wide part of the casing. It kinda makes sense if you look at them (without looking at the gun).
Flat back of the casing, flat back of the magazine.
Edit: more obvious in your hand