The ornamental design for a shoe upper, as shown and described.
FIG. 1 is a first side front perspective view of a shoe upper showing my design;
FIG. 2 is a first side view thereof;
FIG. 3 is a rear perspective view thereof;
FIG. 4 is a second side view thereof; and,
FIG. 5 is a rear view thereof.
The long-and-short broken lines form an unclaimed boundary around at least a portion of the claimed subject matter and form no part of the claim. The even-length broken lines show the remainder of the article, are directed to environmental subject matter, and form no part of the claimed design.