The ornamental design for a displayscreen or portion thereof with icon, as shown and described.
FIG. 1 is a Front View of a display screen or portion thereof with icon showing our new design; and,
FIG. 2 is a Front View of a display screen or portion thereof with icon showing an alternative embodiment of our new design.
The dash-dot broken lines in the drawings illustrate the display screen or portion thereof that forms no part of the claimed design. Moreover, the even broken line showing the landscape background, various text, corner window, and the OK button are provided for the purpose of illustrating environmental structure of a graphical user interface and forms no part of the claimed design.