The ornamental design for a displayscreen or portion thereof with an animatedgraphicaluserinterface, as shown and described.
FIG. 1 is a front view of a display screen or portion thereof with an animated graphical user interface showing a first image;
FIG. 2 is a second image thereof;
FIG. 3 is a third image thereof;
FIG. 4 is a fourth image thereof; and,
FIG. 5 is a fifth image thereof.
The broken lines showing the display screen are included for illustrating portions of the article and form no part of the claimed design.
The appearance of the image transitions sequentially between the images shown in FIGS. 1-5. The process or period in which an image transitions to another forms no part of the claimed design.