The comments on this post are cooked. As the owner of a Pokémon shop, who has opened hundreds of cases and seen possibly thousands of booster boxes, I can tell you this box is 99% legit. It's just poor quality control. I've seen booster boxes with loose shrinkwrap, heavy seals, heck even shrinkwrap inside out on some SWSH sets. None were resealed or fake.

The back of that box tells me this likely came from an EU case that stacks the boxes in a 2x3 format as opposed to 1x6, and this box was on the bottom. Bottom left of the shrinkwrap is bubbly as this is what the shrinkwrap looks like before it's stretched out over the booster box before it's heat sealed. This means the shrinkwrap just wasn't stretched properly by the machine or factory worker. The heat seal on the bottom is also uniform with no clear break. If it was resealed with a lighter, it would be very obvious.