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Rolling Disk Illusion

The eight yellow points seem to be situated on the rim of a disc rolling inside the red circle. Click on "puzzle" check box to see the unexpected motion each point traces in time. Compare this applet with the applet "Disc rolling inside a disc" https://www.geogebra.org/m/2972175 Why/how do the two applets differ? Why/how are the two applets similar?
Adapted from an applet by Branka Milivojevic