Using the Arthemia theme, I selected a few small icons for taxonomy usage, at 35px × 34px. However, something is upscaling it to 164px × 34px. This is part of Ubercart if that makes a difference. It's the only thing we're using taxonomy on.

Since some of the images will be various flags, that much stretching can't really be usable. Any way to adjust it?

The selection source also says:

Only local images are allowed.

Where would the 164x34 come from? uc_thumbnail is set to 35x35.

Is this on arthemia or separate? It's not stretching on other themes.