outline
A person or item in the image is surrounded by an outline (usually white or black and distinct from any lineart in the image) which visibly separates it from the background.
See also
The following tags implicate this tag: aqua_outline, black_outline, blue_outline, brown_outline, green_outline, grey_outline, orange_outline, pink_outline, purple_outline, red_outline, white_outline, and yellow_outline (learn more).