We claim, the ornamental design for a display screen 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; the icon is shown separately for clarity of illustration, on an enlarged scale; and,
FIG. 2 is another front view thereof.
The broken line showing of the display screen forms no part of the claimed design. The broken line showing of the text and graphic elements form no part of the claimed design.