When embedding a flash in a board other than /f/ (e.g. /b/), the space allocated for the flash is a square, even if the flash doesn't have a square aspect ratio.

For example, a wide flash will be allocated a square space like in the picture. The flash will only be played in between the bars, looking ugly. But it gets worse. Some parts of the flash will be played outside of the bars, outright breaking some flashes.