Touch the image and keep your finger pressed against the screen until the Save Image menu appears. Press “Save Image”. The image is saved to Photos.

Now exit Safari, and start Photos. Find the image you saved, and open it until it fills the screen. Press your finger on the image and hold until the navigation menu appears. In the lower left, there is an icon of an arrow jumping out of a frame. Press that button.

A menu comes up allowing you to Use As Wallpaper. Select “Use As Wallpaper”. You can then move and scale the image, if you wish. When happy with the way it looks, select “Set Wallpaper.” You’re done!