In the Chapel of the Holy Cross at Karlštejn, his image is placed on the eastern (epistle) wall of the presbytery behind a dividing metal grille.

Examination of the image using infrared reflectography revealed a fine and detailed underdrawing in the face and a sovereign drapery sketch.

[1] Compared to his masterpieces, the painting with St. Simon is characterized by a harder and more schematic rendering in the incarnations, a certain flattening and simplification of the face, and less plasticity in the drapery.

They repeat architectural motifs that have analogous counterparts in Peter Parler´s works: triangular pennants with quadrillobes and crabs, rosettes and Gothic windows with crosses.

[4] In the Chapel of the Holy Cross, the image of St. Simon is placed next to St. Judas Thaddeus, with whom he shares the feast day of 28 October in the Western Christian Church.