
If you select Fit, the wallpaper image will be enlarged or shrunk height-wise. The resizing is done with proper related perspective and the smaller images are often stretched in this wallpaper setting.
Choosing a Fill fit will enlarge or shrink the image according to your screen’s width to get a proper fit.
Smaller images will set with a border on your screen whereas the larger images will display only the center part of the image leaving the rest out of view.
Choosing a Center fit centers your wallpaper on the screen. Once you are done with the selection, scroll down, and check the drop-down menu of Choose a Fit. You will get options like Fill, Fit, Stretch, Tile, Center, and Span. Center, Fill, Fit, Stretch, Tile, Span – Wallpaper