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 my new design;
FIG. 2 is a front view of a display screen or portion thereof with icon, showing an alternative embodiment of the new design; and,
FIG. 3 is a front view of a display screen or portion thereof with icon, showing an alternative embodiment of the new design.
The dot-dash broken lines illustrating portions of the display screen are included for the purpose of illustrating environmental structure and form no part of the claimed design.