Poster Bug?

It looks like you're using an image with transparent, where the right side is fully transparent? If it's this image, there is indeed plenty of transparent space on the right side... I would recommend removing the transparent space (this would also improve image quality and memory consumption)

The game doesn't display the backface of posters mirrored, so if the poster consists of text, it's readable from both sites. Not sure if we should change that... if we change it, it might cause problems for people who already rely on this behaviour

The best thing to do with self-created PNGs is to put the object in the middle and cut away the rest as red explained.

That had worked for me for years.