So, I just happened across this video from May 12, 2012. Quoting: S0L4RN1GHTM4R3
This very well could be the moon, however, if that were the case, it wouldn't be illuminated as it quite obviously is.
It's nothing you suggested, in fact it's much simpler than that. It's a filter flare. Holding ones' sunglasses up to a camera is not the proper way to image the sun. Furthermore, most cell phone and similar cheap cameras have a piece of glass or plastic protective covering in front of the lens, which automatically provides the surface needed for the formation of a filter flare.
Filter flares are a bit distinct from lens flares in that the reflection is generated by a surface exterior to the lens and produces a reflection which is essentially an exact, but dimmer, copy of whatever the bright light source is, in this case the sun. Thus you see a bright white ball near the sun. They also tend to move less as you move the camera than other lens flares in the image. Here's what you'll never see any of these Nibiru claimants do during their video.
It's a very simple test. Cover up the sun with your finger from the perspective of the camera. If it makes the filter flare disappear, then that's all it was. In this case the only reason it disappeared was because it was drowned out by the over-exposed backlit cloud.
If you watch carefully though, you can tell the filter flare is just a reflection of the sun; you can see it start to dim and show the shadow of the cloud in front of it BEFORE the cloud actually reaches the position of the filter flare. That's because the cloud is already starting to float in front of the sun, which is the true source of the flare. Pause it at 0:38 to see what I mean. By that point the entire flare is now dimmer than it was because the sun is completely covered by the cloud, and a thicker part of the cloud blocks even more of it towards the bottom, you can see a slight "spike" shape in the image of the flare. That's the sun, covered by the cloud. Once the cloud floats over to the filter flare's position you can't see it anymore because the cloud itself is brighter than the flare, in fact it's completely saturating those pixels until about 1:24 when it starts to appear again in front of the cloud as the sun is now emerging, allowing the filter flare to be seen again. At 1:33 it's painfully obvious that the filter flare is appearing in front of the cloud, not behind it; you can't see what should be the edge of the cloud dimming the left half of it at all.