The ornamental design for a displayscreen or portion thereof with transitional graphical user interface, as shown and described.
FIG. 1 is a first image in a sequence for a display screen or portion thereof with transitional graphical user interface, showing our new design in a first embodiment;
FIG. 2 is a second image in a sequence thereof;
FIG. 3 is a third image in a sequence thereof;
FIG. 4 is a fourth image in a sequence thereof;
FIG. 5 is a fifth image in a sequence thereof;
FIG. 6 is a sixth image in a sequence thereof;
FIG. 7 is a first image in a sequence for a display screen or portion thereof with transitional graphical user interface, showing our new design in a second embodiment;
FIG. 8 is a second image in a sequence thereof;
FIG. 9 is a third image in a sequence thereof;
FIG. 10 is a fourth image in a sequence thereof;
FIG. 11 is a fifth image in a sequence thereof; and,
FIG. 12 is a sixth image in a sequence thereof.
The outermost broken lines illustrate a smartphone on which the display screen or portion thereof and graphical user interface are embodied, and form no part of the claimed design. The remaining dashed broken lines, illustrating the display screen or portion thereof and the graphical user interface, also 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 and 7-12. The process or period in which one image transitions to another image forms no part of the claimed design.