If you select a glyph and a background image, and then go to Path > Transformations to transform them, the image will be transformed twice. Refer to the sample image below.
(When you only select the image the same thing will happen.)
With the Transformations feature in the side panel you can transform images properly.
However, when creating Japanese glyphs, you cannot use it to transform based on the baseline.
So could you fix this problem?