Off the top of my head, I can think of several reasons that the reflections of the sun or lander in an image of an Apollo astronaut are larger than they "should" be. Of course, since they are pictures of the actual event, they are exactly *as* they should be, but in any case:
1. Reflections in a curved surface vary in size depending on their apparent position on the surface. Look at the flag in the picture. Does the reflection prove that the flag is not a rectangle? This holds true for all non-point sources. In this context, the sun and its attendant corona are definately not a point source.
2. On video stills (which at least one of the posted pictures are), "bloom" of a bright object (such as a reflection of the sun) will make the object appear larger on the video than reality. This would be especially true of stills from Apollo 14, which used a vidicon camera. If you view the EVA TV from Apollo 14, you will see plenty of reflections that bloom much larger than they would appear to a person there. On Apollo 15 and later missions, the TV camera used a silicon sensor which was much less susceptable to bloom (or saturation, as it should be called for a non vidicon imaging system.)
3. The Apollo visor is made of Lexan. The material is incredibly hard, yet easily scratched. The lunar environment is not kind to equipment, since everything is coated with dust. The area that is reflecting the sun in the Gemini/Apollo comparison picture posted is an area of the visor that is routinely scratched by the use of a sun shade that is slid over the visor. You can see the sun shade partially deployed in one of the other posted pictures. The scratched surface of the lexan will act to diffuse the reflection of a bright object (making it appear larger and out of focus.)
To people who pore over these pictures and look for "evidence", I say send me a large enough set of pictures (100 or so) from any event in their own lives, and I will be able to find "proof" that the event never took place.