The Healing Brush tool automatically blends the source with the destination.
As you can see, using the Clone Stamp to clone the puppy’s eye results in a
straight copy of the pixels, while the Healing Brush does a much better job
of blending with the background.
This built-in intelligence proves extremely helpful when cloning a subject
with diverse colors, textures and lighting conditions. Using the Clone Stamp
in these situations can leave you with a lot of noticeably patchy spots that
really stand out from the surrounding area.