Display Screen or Portion Thereof with Transitional Graphical User Interface

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

FIG. 2 is a second image thereof;

FIG. 3 is a third image thereof;

FIG. 4 is a front view of a second embodiment of a display screen or portion thereof with a transitional graphical user interface showing our new design;

FIG. 5 is a second image thereof;

FIG. 6 is a third image thereof;

FIG. 7 is a front view of a third embodiment of a display screen or portion thereof with a transitional graphical user interface showing our new design;

FIG. 8 is a second image thereof;

FIG. 9 is a third image thereof;

FIG. 10 is a front view of a fourth embodiment of a display screen or portion thereof with a transitional graphical user interface showing our new design;

FIG. 11 is a second image thereof;

FIG. 12 is a third image thereof;

FIG. 13 is a front view of a fifth embodiment of a display screen or portion thereof with a transitional graphical user interface showing a first image in the sequence showing our new design;

FIG. 14 is a second image thereof;

FIG. 15 is a third image thereof;

FIG. 16 is a front view of a sixth embodiment of a display screen or portion thereof with a transitional graphical user interface showing a first image in the sequence showing our new design;

FIG. 17 is a second image thereof;

FIG. 18 is a third image thereof;

FIG. 19 is a front view of a seventh embodiment of a display screen or portion thereof with a transitional graphical user interface showing a first image in the sequence showing our new design;

FIG. 20 is a second image thereof;

FIG. 21 is a third image thereof;

FIG. 22 is a front view of an eighth embodiment of a display screen or portion thereof with a transitional graphical user interface showing a first image in the sequence showing our new design;

FIG. 23 is a second image thereof;

FIG. 24 is a third image thereof;

FIG. 25 is a front view of a ninth embodiment of a display screen or portion thereof with a transitional graphical user interface showing a first image in the sequence showing our new design;

FIG. 26 is a second image thereof;

FIG. 27 is a third image thereof;

FIG. 28 is a front view of a tenth embodiment of a display screen or portion thereof with a transitional graphical user interface showing a first image in the sequence showing our new design;

FIG. 29 is a second image thereof; and,

FIG. 30 is a third image thereof.

The outermost dash-dot broken lines in the drawings illustrate the display screen or portion thereof and form no part of the claimed design. The other broken lines in the drawings illustrate portions of the transitional graphical user interface that form no part of the claimed design.

The appearance of the images transitions between the images shown in FIGS. 1 through 3 , between the images shown in FIGS. 4 through 6 , between the images shown in FIGS. 7 through 9 , between the images shown in FIGS. 10 through 12 , between the images shown in FIGS. 13 through 15 , between the images shown in FIGS. 16 through 18 , between the images shown in FIGS. 19 through 21 , between the images shown in FIGS. 22 through 24 , between the images shown in FIGS. 25 through 27 and between the images shown in FIGS. 28 through 30 , respectively. The process or period in which one image transitions to another forms no part of the claimed design.