The painter from Theys used a geometric composition to create a decoration that fits in with the architecture of the large reception room. This composition has three registers: a false hanging in the lower part, a geometric network in the center, and a frieze of coats of arms in the upper part.

The central part is made up of large squares divided into four smaller squares but also divided by the diagonals so that one large square is made up of eight right-angled triangles. This complex layout was made with a few essential tools such as a compass, plumb line, chalk line, and probably a level.

The historiated medallions, in the form of quatrefoils, are always located at the intersection of the diagonals, while the plant medallions (simple circles) are located in the middle of the four sides of the large squares, at the intersection of a vertical and a horizontal line.

The decoration follows all the reliefs formed by the various features of the architecture: the windows, the washbasin, the fireplace, etc. It is symmetrically distributed on the south-west and north-west walls, while it fits on the north-east and south-east walls, which are slightly larger than the other two. This shows that the painter used a fixed reference measurement instead of dividing each wall into an equal number of squares.