The Curious Case of the Dot (Edition 2)

Now let's look at the same exercise in the subsequent edition (2) of the book. Some of the edition revisions are overt and intentional (color, additional figures), but others differences seem slight and incidental, and some differences seem outright accidental. (It is worth noting that the edition 3 instance of this exercise is identical [more or less] to the edition 2 instance.)

To zoom out, keep pressing [command and -] (on a mac) or [control and -] (on a pc). To return to the original scale, press [command and 0] (on a mac) or [control and 0] (on a pc). If you are on a pad or a phone, pinch to zoom out.

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From The Mechanism of Meaning, Edition 2:

Where is the dot in the left-hand circle section? Why is the dot present in the circle section of the accompanying installation documentation? Is this dot discrepancy intentional? Is it a misprint (and if so, why did they re-misprint it again in Edition 3)? Are those extra subtle dots actually just dust on the book page? Are they dust on my digital camera? (These are my books. I took these pictures.) Or are they dust on your screen? (Scroll down for detail views.)

Edition 2 [Detail, left-hand]

Edition 2 [Detail, installation documentation]