This comment has been posted in the on line conference on Pictures in Cognition and in Science
Stoffregen writes: "Our ability to see meaningful features of things is (so far) much greater than our ability to quantify meaning in syntactic codes (e.g., programming languages) and that is why artists remain better than computers for this type of task"
Still, lithic drawing as many other cases of "scientific" drawing relies on partly codified meaninigs, as the Lucile Addington's manual mentioned by Lopes shows. Only trained archaeologists can extract the relevant, meaningful features from the stones, and in this sense, they have been partly "programmed" through their archaeological studies.
There are so many manual abilities in many domains of science that are difficult to automatize, such as for example collecting butterflies for entomological purposes, but this is a much broader question and I don't see why it should be so obvious that in the case of lithic drawings manual abilities will always have an advantage on computer drawing.
Also, there are two questions that are often confused in this debate: one is why drawing should be better than photographs (and the general answer is: because it allows to discriminate relevant features that a photo, although accurate, is not able to make salient enough). The other question is: is manual drawing intrinsically superior to machine drawing (and for this second question, I still have not seen a clearcut answer).