Yes, that is dihedral. The upper surface of the tapered wing is flat, but structurally, the wing has dihedral. The centers of the tips are raised compared to the center of the root. A truly flat tapered wing would have the leading and trailing edges flat, the upper and lower surfaces would not be flat (following the taper), and the tips would be on the same center as the root.

Years ago, I built a Lanier Laser 200, and the wing was joined with the top on a flat surface, using this same principal. The dihedral was thus designed in as a goof proof process, even I couldn't mess that one up!