I'll have a look, but my first impression is that all the elements could appear as single, double or treble curves. These appear either upright, flat, or leaning (bot l to top r). Most of these also appear in an inverted form. thus we have 3 symbols, each in one of 6 orientations. giving 18 possible symbols.
Most short messages can be made with this few letters, and any message can have itself shortened (and the length of required alphabet reduced) by (for example) removing all vowels, without too great a loss of meaning.