FIG. 1 is a front view of a first embodiment of a display screen or portion thereof with transitional graphical user interface showing a first image in a sequence, showing our new design;
FIG. 2 is a front view showing a second image thereof;
FIG. 3 is a front view showing a third image thereof;
FIG. 4 is a front view showing a fourth image thereof;
FIG. 5 is a front view showing a fifth image thereof;
FIG. 6 is a front view showing a sixth image thereof;
FIG. 7 is a front view of a second embodiment of a display screen or portion thereof with transitional graphical user interface showing a first image in a sequence, showing our new design;
FIG. 8 is a front view showing a second image thereof;
FIG. 9 is a front view showing a third image thereof;
FIG. 10 is a front view showing a fourth image thereof;
FIG. 11 is a front view showing a fifth image thereof;
FIG. 12 is a front view of a third embodiment of a display screen or portion thereof with transitional graphical user interface showing a first image in a sequence, showing our new design;
FIG. 13 is a front view showing a second image thereof;
FIG. 14 is a front view showing a third image thereof;
FIG. 15 is a front view showing a fourth image thereof;
FIG. 16 is a front view showing a fifth image thereof;
FIG. 17 is a front view of a fourth embodiment of a display screen or portion thereof with transitional graphical user interface showing a first image in a sequence, showing our new design;
FIG. 18 is a front view showing a second image thereof;
FIG. 19 is a front view showing a third image thereof;
FIG. 20 is a front view showing a fourth image thereof;
FIG. 21 is a front view showing a fifth image thereof;
FIG. 22 is a front view of a fifth embodiment of a display screen or portion thereof with transitional graphical user interface showing a first image in a sequence, showing our new design;
FIG. 23 is a front view showing a second image thereof;
FIG. 24 is a front view showing a third image thereof;
FIG. 25 is a front view showing a fourth image thereof;
FIG. 26 is a front view showing a fifth image thereof;
FIG. 27 is a front view of a sixth embodiment of a display screen or portion thereof with transitional graphical user interface showing a first image in a sequence, showing our new design;
FIG. 28 is a front view showing a second image thereof;
FIG. 29 is a front view showing a third image thereof;
FIG. 30 is a front view showing a fourth image thereof; and,
FIG. 31 is a front view showing a fifth image thereof.
The outer perimeter illustrated by a pair of even-dash broken lines illustrates a display screen or portion thereof and forms no part of the claimed design. The remaining even-dash broken lines illustrating portions of the graphical user interface form no part of the claimed design. The dot-dash broken lines in the figures illustrate a boundary of the claimed design and form no part of the claimed design.
The appearance of the transitional graphical user interface sequentially transitions between the images shown in FIGS. 1-6, FIGS. 7-11, FIGS. 12-16, FIGS. 17-21, FIGS. 22-26 and FIGS. 27-31. The process or period in which one images transitions to another forms no part of the claimed design.