The ornamental design for a shoe upper, as shown and described.
FIG. 1 is a side view of a shoe upper showing my new design;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a side view of a shoe upper showing an alternative embodiment of my new design in grayscale depiction; and,
FIG. 4 is a rear perspective thereof.
The broken lines immediately adjacent to the shaded and photographic area represent unclaimed boundaries of the design. The broken lines showing the remainder of the shoe are for environmental purposes only and form no part of the claimed design. The contrast in shading in FIGS. 1-2 represents a contrast of appearance and no specific color, material, or texture is claimed.