Display screen or portion thereof with transitional computer graphical user interface

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

FIG. 1 is a front view of a first image in a sequence of a first embodiment of a display screen or portion thereof with transitional computer graphical user interface according to the claimed design; and

FIG. 2 is a second image thereof;

FIG. 3 is a third image thereof;

FIG. 4 is a fourth image thereof;

FIG. 5 is a front view of a first image in a sequence of a second embodiment of a display screen or portion thereof with transitional computer graphical user interface according to the claimed design;

FIG. 6 is a second image thereof;

FIG. 7 is a third image thereof; and,

FIG. 8 is a fourth image thereof.

The appearance of the transitional image sequentially transitions between the images shown in FIGS. 1-4 in the first embodiment and FIGS. 5-8 in the second embodiment. The process or period in which an image transitions to another image forms no part of the claimed design.

The shadow-like shading shown near the left and right edges of the screen and along the sides and bottom of the card features that are shown toward the bottom of the figures is included in the claimed design.

The vertical dotted line shown within the graph depicted in each of FIGS. 2-4 and FIGS. 6-8 is a feature that is part of the claimed design.

The longer-dash broken lines illustrate an electronic device. The intermediate-length broken lines illustrate the perimeter of a display screen. The remaining broken lines illustrate features within the graphical user interface. The broken lines form no part of the claimed design.