Display Screen or Portion Thereof with Transitional Graphical User Interface

FIG. 1 is a front view of a display screen or portion thereof with transitional graphical user interface showing a first image in a sequence according to an embodiment of the claimed design, where the portions of the transitional graphical user interface that contrast with the display screen or portion thereof are indicated using a slanted line hatching pattern;

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

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

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

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

FIG. 6 is a front view of a sixth image in the sequence;

FIG. 7 is a front view of a seventh image in the sequence; and,

FIG. 8 is a front view of an eighth image in the sequence.

The outermost broken line rectangle illustrates a display screen or portion thereof and form no part of the claimed design. The remaining broken lines illustrate portions of the graphical user interface that form no part of the claimed design.

The appearance of the transitional image sequentially transitions between the images shown in FIG. 1 to FIG. 8 in the embodiment. The process or period in which an image transitions to another image forms no part of the claimed design.