The ornamental design for a picturebook, as shown and described.
FIG. 1 is a front and top perspective view of a picture book, showing my new design;
FIG. 2 is a rear and bottom perspective view thereof;
FIG. 3 is a front elevation view thereof;
FIG. 4 is a rear elevation view thereof;
FIG. 5 is a left side elevation view thereof;
FIG. 6 is a right side elevation view thereof;
FIG. 7 is a top plan view thereof;
FIG. 8 is a bottom plan view thereof;
FIG. 9 is another perspective view thereof, shown in an alternative position; and,
FIG. 10 is an enlarged view of a portion labeled, ‘FIG. 10’ in FIG. 1.
The evenly spaced broken lines immediately adjacent to the claim depict the bounds of the claimed design, while all other evenly spaced broken lines are directed to environment. The dash dot dash broken lines in FIGS. 1 and 10 are for the purpose of depicting the boundary lines of the enlarged views and form no part of the claim.