It is interesting that the hotspot in the Solar Eclipse photo above is off-center. That appears hard to describe with the theory that the darkening is a physical property of the sun's dim layers millions of miles behind the Moon.
Under the FE projection scenario, the hotspot being off center when something near the light source interferes with it does make some sense. Consider a wall projector. If you put your hand or object near the light source of a wall projector, it is more possible to change where the hotspot is on the wall due to close range light deflection.
According to RE the phenomenon of the dimmer rim of the Sun is called Limb Darkening, and is a physical property of the sun having different temperatures at different layers:
http://abyss.uoregon.edu/~js/glossary/limb_darkening.htmlLimb Darkening:
Limb darkening is the gradual decrease in brightness of the disk of the Sun or of another star as observed from its centre to its edge, or limb. This phenomenon is readily apparent in photographs of the Sun. The darkening is greatest for blue light, amounting to a drop of as much as 90 percent from the Sun's photosphere to its outer atmospheric regions. Such limb darkening occurs because the solar atmosphere increases in temperature with depth. At the centre of the solar disk, an observer sees the deepest and warmest layers that emit the most light. At the limb, only the upper, cooler layers that produce less light can be seen. Observations of solar limb darkening are used to determine the temperature structure of the Sun's atmosphere. Information derived from such observations is applied in studying other stars.
Excerpt from the Encyclopedia Britannica without permission.
If this darkening is a physical property of the layers of the Sun, it interesting that the Moon can sometimes seem to cause the Sun to darken up, despite that the Sun is supposedly 92 million of miles behind the Moon.
Here is another Solar Eclipse photo of the Sun, from Joshua Tree Park on October 23, 2014:
https://www.flickr.com/photos/joshuatreenp/15609084861Slight adjustments, see arrows:
The edge of the Moon caused the body of the Sun to darken to an luminosity similar to the Sun's edges.
It seems that this effect doesn't happen in an obvious manner all the time:
https://www.edgeonscience.com/annular_solar_eclipse/In these cases, it might be that the hotspot is off center a bit like in the first eclipse photo in the previous post, but close enough to the center that it is difficult to tell. Different Sun-Moon distances or different mediums between the Sun and Moon in FE, can possibly cause different effects. In RE it's supposed to be a relative vacuum between the Moon and Sun.
From the above image the central hotspot is potentially slightly off-center, shifted slightly to the left of center of the sun disk:
Photos like this may be ambiguous. But that the Moon should ever seem to cause the Sun to obviously darken at all, or cause the hotspot to be obviously off-center, in some pictures, is certainly deserving of investigation.