Display screen or portion thereof with transitional graphical user interface

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

FIG. 2 is a front view of the second image thereof;

FIG. 3 is a front view of the third image thereof;

FIG. 4 is a front view of the fourth image thereof;

FIG. 5 is a front view of the fifth image thereof;

FIG. 6 is another view of FIG. 1 , but shown without the broken lines for clarity of illustration;

FIG. 7 is another view of FIG. 2 , but shown without the broken lines for clarity of illustration;

FIG. 8 is another view of FIG. 3 , but shown without the broken lines for clarity of illustration;

FIG. 9 is another view of FIG. 4 , but shown without the broken lines for clarity of illustration;

FIG. 10 is another view of FIG. 5 , but shown without the broken lines for clarity of illustration;

FIG. 11 is an enlarged view of the encircled portion in FIG. 6 ;

FIG. 12 is an enlarged view of the encircled portion in FIG. 7 ;

FIG. 13 is an enlarged view of the encircled portion in FIG. 8 ;

FIG. 14 is an enlarged view of the encircled portion in FIG. 9 ; and,

FIG. 15 is an enlarged view of the encircled portion in FIG. 10 .

The appearance of the transitional image sequentially transitions between the images shown in FIGS. 1 to 5 . The process or period in which one image transitions to another forms no part of the claimed design.

The outer perimeters illustrated by broken lines in the drawings depict a display screen or portion thereof and forms no part of the claimed design. The remaining broken lines depict portions of graphical user interface that form no part of the claimed design.

The dot-dot-dash broken lines encircling portions of the claimed design that are illustrated in enlargements form no part of the claimed design.