The ornamental design for a head mount display, as shown and described.
FIG. 1 is a front perspective view of a head mount display showing our new design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a left side elevation view thereof;
FIG. 5 is a right side elevation view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof;
FIG. 8 is a rear perspective view thereof; and,
FIG. 9 is the front perspective view of FIG. 1 showing the head mount display with a visor to be combined therewith.
The visor shown in evenly-dashed broken lines in FIG. 9 forms no part of the claimed design. The remaining evenly-dashed broken lines in the drawings illustrate portions of the head mount display that form no part of the claimed design.