In the brief summary of the main points of the discussion given below, bullets are used to provide the main points, with text annotations as needed. While the bullets were issues raised during the discussion, the points made in the annotations may not have been. It's clear that sketches can be used as a memory aid, to evaluate a proposed solution, to deliberately attempt to trigger associations with known previous designs or known problem decompositions, to refine requirements, etc. These primitives need to have meaning if the representation is to be useful. The mere act of representing a sketch makes a commitment to a particular interpretation of the marks.
More interpretation leads to a smaller representation and more direct use of the representation.
Sketching can both help and hinder designing. Sketching places demands on the user to supply information that can then be recorded in the sketch. If the sketch is intended to be a precise record of a detailed portion of the design then the user is required to include all the details. Depending on one's point of view, there are many possible things that might be considered a feature. For example, in time, one might be interested in a pause, in a change of speed during the drawing of a line, or the number of marks per minute.