What is claimed is the ornamental design for a beach chair with flag design, as shown and described.
FIG. 1 is a perspective view of a beach chair with flag design, illustrated in an expanded configuration, showing my new design;
FIG. 2 is a front elevational view thereof, illustrated in the expanded configuration;
FIG. 3 is a rear elevational view thereof, illustrated in the expanded configuration;
FIG. 4 is a left-side elevational view thereof, illustrated in the expanded configuration, the right-side elevational view being a mirror image thereof;
FIG. 5 is a top plan view thereof, illustrated in the expanded configuration;
FIG. 6 is a bottom plan view thereof, illustrated in the expanded configuration; and,
FIG. 7 is a perspective plan view thereof, illustrated in a collapsed configuration.