I claim the ornamental design for a height-adjustable furniture piece, as shown and described.
FIG. 1 is a front perspective view of the height-adjustable furniture piece in accordance with our new design, where the height-adjustable furniture piece is shown connected to a wall.
FIG. 2 is a left side view thereof;
FIG. 2A is an enlarged view of the portion within the dash-dot line box shown in FIG. 2;
FIG. 3 is front view thereof;
FIG. 4 is right side view thereof;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom plan view thereof.
The broken lines in the figures are to illustrate environmental structure only and form no part of the claimed design. The dash-dot lines in the figures are to illustrate boundaries and also form no part of the claimed design.