Display screen or portion thereof with a transitional graphical user interface

The present application is also related to U.S. patent application Ser. No. 16/860,818, filed Apr. 28, 2020, entitled “Systems and Methods for Short Term Persistence by Unlocking Additional Symbol Positions, ” the disclosure of which is hereby incorporated by reference in its entirety.

FIG. 1 is a front view of a display screen or portion thereof with a transitional graphical user interface showing a first image in a sequence according to our new design;

FIG. 2 is a front view thereof showing a second image in the sequence;

FIG. 3 is a front view thereof showing a third image in the sequence;

FIG. 4 is a front view thereof showing a fourth image in the sequence;

FIG. 5 is a front view thereof showing a fifth image in the sequence;

FIG. 6 is a front view thereof showing a sixth image in the sequence; and,

FIG. 7 is a front view thereof showing a seventh image in the sequence.

The appearance of the transitional image sequentially transitions between the images shown in FIGS. 1 - 7 . The process or period in which one image transitions to another image forms no part of the claimed design. The outermost broken line illustrates a display screen or portion thereof and forms no part of the claimed design. Stippling in the drawings is used to indicate a contrast in appearance, with no specific color or other feature being claimed. The remaining broken lines represent elements of the display screen or portion thereof with a transitional graphical user interface that form no part of the claimed design.