The ornamental design for a side element of a shoe upper, as shown and described.
FIG. 1 is a side elevational view of a side element of a shoe upper showing
my new design;
FIG. 2 is a top plan view thereof;
FIG. 3 is a front elevational view thereof; and,
FIG. 4 is a rear elevational view thereof.
The broken line showing of a shoe and the remaining portion of the upper
shown in FIGS. 1-4 is for illustrative purposes only and forms no part of
the claimed design.