The box was made with los cost materials, the Apple logo from the original case was a little bit deeper on the original one, the text from interior case is more legible on the original one and the interior material has a darker color on the fake one.
I once bought an "authentic" Apple leather case for my old 6 Plus on Amazon for about $16 (this was last year btw). The box was spot on, the interior looked identical and even the creases/stamping of the interior microfiber/leather split was exact. But I knew it was fake by how it felt and wore in later on--it stained differently, the leather felt weird at times depending on humidity and the apple logo was very faint and not as embossed as an original in photos. I also noticed tiny things like one speaker hole would be slightly covered by one of the bottom corners.
It was scary close in comparison--the only way I found out was later on but I just said screw it. This time, I bought a real one at Best Buy for my 8 Plus. It was expensive but I KNOW it's real and as time goes by the leather is a joy to feel and use and definitely has a more authentic feel of leather weathering.