Display Screen or Portion Thereof with a Transitional Graphical User Interface for an Interactive Content Overlay

FIG. 1 is a front view of a first image of a display screen with a transitional graphical user interface for an interactive content overlay;

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

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

The appearance of the graphical user interface sequentially transitions between the images shown in FIGS. 1 - 3 . The process or period in which one image transitions to another image forms no part of the claimed design.