For large images, this might make a difference. My recommendation is to turn off preloading for larger images, and use separate versions for different layouts. For smaller images (not background images), then you can just do your resizing between layouts.
I don't think it is entirely necessary to use separate images for Laptop / Desktop, since both will be about the same size -- but up to you. Just make sure you turn off preloading for these large images so they they are not preloaded on all device sizes.