The ornamental design for an arteasel, as shown and described.
FIG. 1 is a perspective view of the art easel showing my new design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a side elevation view thereof, the opposite side elevation view being identical to the side shown;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof;
FIG. 7 is a perspective view thereof opened; and,
FIG. 8 is a perspective view thereof attached to a tripod.
The broken lines showing portions of the art easel in FIGS. 1-3 and 6-8 and a tripod in FIG. 8 are included to show features that form no part of the claimed design.