Display screen or portion thereof with transitional icon

A portion of the disclosure of this patent document contains material which a claim for copyright is made. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the US Patent and Trademark Office patent file or records, but reserves all other copyrights whatsoever.

FIG. 1 is a front view of the first image in a sequence for a display screen or portion thereof with transitional icon showing the new design;

FIG. 2 is the second image thereof;

FIG. 3 is the third image thereof; and,

FIG. 4 is the fourth image thereof.

The appearance of the icon sequentially transitions between the images shown in FIGS. 1-4 . The process or period in which the icon transitions to another forms no part of the claimed design.

The broken lines show in the drawings illustrate portions of the display screen or portion thereof with transitional icon that forms no part of the claimed design.