We claim the ornamental design for an automatic shampoo machine, as shown and described.
FIG. 1 is a front perspective view of an automatic shampoo machine of the present invention;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a first side view thereof;
FIG. 5 is a second side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof;
FIG. 8 is a front perspective view thereof shown with the front panel in an open position;
FIG. 9 is a cross-section view taken along the line 9-9 of FIG. 8; and,
FIG. 10 is a cross-section view taken along the line 10-10 of FIG. 2.
The broken lines shown represent unclaimed subject matter and form no part of the claimed design. Additionally, the unevenly broken lines in the drawings define the limits of the claimed design.