To resize a picture for avatar/icon form, you must have a perfect (or almost completely perfect) square. This is because any number that has the same width and height can be resized to 100 x 100 or 50 by 50. Here are some examples.
1) Original Picture: 302 x 302 pixels
Avatar Size: 100 x 100 pixels
Icon Size: 50 x 50 pixels
2) Original Picture: 400 x 400 pixels
Avatar Size: 100 x 100 pixels
Icon Size: 50 x 50 pixels
Your Johnny Depp Picture is 640 x 453 pixels. Watch what happens when it is resized to 100 x 100 and 50 x 50.
Avatar Size
Icon Size
Because it is not equal length & equal width on both sides, (a square), it cannot be accurately resized to fit a perfect square figure unless cropped/cut/edited in a paint program.
