Because that layer (mute_over) is as big as the size of the image (the yellow dashed line all around shows the layer size).
Go to the top menu "Layer > Crop to content" the offset should now show up as the layer is smaller than the image size (canvas), and not bigger than the size of the button.
Go to the top menu "Layer > Crop to content" the offset should now show up as the layer is smaller than the image size (canvas), and not bigger than the size of the button.
Patrice