The ornamental design for a pictureframebookend, as shown and described.
FIG. 1 is a front perspective view of the present invention;
FIG. 2 is a rear perspective view of the present invention;
FIG. 3 is a front elevational view of the invention;
FIG. 4 is a rear elevational view of the invention;
FIG. 5 is a left side elevational view of the invention;
FIG. 6 is a right side elevational view of the invention;
FIG. 7 is a top plan view of the invention; and,
FIG. 8 is a bottom plan view of the invention.
It should be appreciated that the broken line illustrations shown in FIG. 4 are for illustrative purposes only and form no part of the claimed invention.