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:
Flat back of the casing, flat back of the magazine.
Edit: more obvious in your hand