When reftest analyzer shows magnified pixels, there is a seemingly random offset between the mouse position and the magnified position. The reason for this is that reftest analyzer assumes all images have 800 * 1000 pixels but actually the test images have varying sizes.
It's currently possible to step through the test results using the <kbd>N</kbd> and <kbd>P</kbd> keys, and you can also switch between test and reference images with the <kbd>T</kbd> key.
However if you want to highlight the differences, that can only be done by clicking. This has always annoyed me somewhat, so this patch adds support for toggling the differences view with the <kbd>D</kbd> key.