I'm in Laptop Edge, always using touchpad mouse. I cannot resize the accent image by dragging the somewhere border of accent image if it's placed opposite-somewhere, as example if the accent image is up (Top aspect), the border for resizing is the bottom of the image, it excludes from background layout. And I say as a bug, because I see the option to resize the accent image through auto change the mouse icon, however it's hard to do it and needs a clicking skill or much time.