The ornamental design for a lift-up laptop computer workstation, as shown and described.
FIG. 1 is a perspective view of a lift-up laptop computer workstation in an upright orientation having the display in an upright orientation and disposed above the workstation surface in an outwardly facing orientation thereof;
FIG. 2 is a right side view and a mirror image of the left side of the lift-up laptop computer workstation in the lifted configuration above the workstation surface thereof;
FIG. 3 is a front view of the lift-up laptop computer thereof; and,
FIG. 4 is a rear view of the lift-up laptop computer workstation.