The ornamental design for a displayscreen or portion thereof with icon, as shown and described.
FIG. 1 is a front view of a first embodiment of an icon, shown without a display screen for ease of visibility;
FIG. 2 is a front view of a second embodiment of an icon, shown without a display screen for ease of visibility;
FIG. 3 is front view of a third embodiment of an icon, shown without a display screen for east of visibility; and,
FIG. 4 is a front view of a display screen or portion thereof with icon, showing my novel design.
The broken lines illustrate the display screen or portion thereof and form no part of the claimed design. The broken lines illustrate portions of the icon and form no part of the claim design.