Take more up-close pictures of the cartridge, front and back. Just a picture of the box can't tell much, but I doubt it's original.

1- Look at the Nintendo seal at the sticker, it should be shiny and GOLD in colour, fake cart will be reddish brown and won't shine in light.

2- Look at the pins at the back, original cart should be gold, not copper.

3- The top of an original cart should have a square mark, while a fake one will just be smooth. You can feel the mark with your finger.

The quality of the plastic is really different, the original one has a really smooth texture, just feels good.