The ornamental design for a magnetichairextensiondisplay, as shown and described.
FIG. 1 is a perspective view of my magnetic hair extension display;
FIG. 2 is a close-up view of the portion designated as 2 in FIG. 1;
FIG. 3 is a front view of the embodiment shown in FIG. 1;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top view thereof; and,
FIG. 8 is a bottom view thereof.
The broken lines in the drawing depicting the circular element on the rear of the magnetic hair extension display are for illustrative purposes only and form no part of the claimed design.