I checked VNDB and the game was only released in 1280x720 for PC. It was released in 1920x1080 but only on the PS4 and only in Japan. There's no way that what you uploaded was native resolution.

If you'll click on the copyright tag we have for the game, you'll notice that all the other CGs we have from the game are 1280x720 too.

I don't know where to find the original image, so I can't help you with the repost.

Edit: We also don't approve screenshots, so keep that in mind.