I claim the ornamental design for an adjustable desk stand, as shown and described.
FIG. 1 is a perspective view of an adjustable desk stand, showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left view thereof;
FIG. 5 is a right view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof; and,
FIG. 8 is a perspective view of an adjustable desk stand shown in an environment of use.
In FIG. 8, the broken lines depicting a table top are representing environmental subject matter that forms no part of the claimed design. All other broken lines are depicting portions of the article that form no part of the claimed design.