The image of the famous Mona Lisa is intended to create a state of visual
confusion; one that may induce an afterimage.
Once you have looked at the animated visual for a while, look at something
white, and pay attention to your phenomenal experience. Does
your afterimage seem like real objects that are "out there", or do they
seem to be coming from somewhere internally. Can you focus on the
experience itself, or do you keep referring to the description of the afterimage?
WHAT WOULD TYE SAY?
Like in previous examples about pain clauses, Tye says that the phrase "an F image" where F is a color or shape term (ex: "a green, square afterimage"), creates an intensional context. There are no such things as perfect squares in the real world, yet we can still have a square afterimage. Regarding phrases about color, we can not make the same logical assumptions as we can in normal non-intensional contexts: watch...
The afterimage in green.
Green is the color of Granny Goose Apples.
The afterimage is the color of Granny Goose Apples.
The conclusion is not necessarily true, because there are many shades of green that we are able to perceive (fine grained perception). The color of the afterimage in the above case may have been nothing like the bright green of Granny Goose Apples. So, once again there seems to be a special context created by color clauses (like pain clauses, etc.).
Like in the examples with pain clauses, Tye sees afterimages as representing something more than just seeing something fuzzy, green, and square. An afterimage represents something that is happening optically. Representations can be about things both real (like a pain), or unreal (like wishing for pink elephant). Since there really is no square, green, fuzzy object out there, Tye says that an afterimage is a misrepresentation, caused by an abnormal sensory experience. This event is the real context, and the afterimage is a representation of this real event, namely the abnormal sensory experience. Finally, Tye concludes that afterimages are intentional.