Here's a very good example of the pixel bleeding that can be caused by very bright objects in an otherwise dark (through that particular filter) frame.

Animation of Sky Bleed

This hasn't been seen to this degree in other images since the sky usually takes up a greater percentage of the sky, when it would push the bright end of the histogram past the cutoff point sooner, thus ending the exposure. If I'm looking at this right, and it isn't an affect of the stretching or JPG creation, the sky portion of the image reached full bin on the ccd long before the exposure ended, unfortuntely bleeding out the nearby pixels. Its unfortunate that the histogram method doesn't seem to pay attention to smaller percentages reaching full bin long before the histogram reaches its critical point.
Hopefully we'll get some shorter, manually timed exposures of the heatshield, which also bled out in this Sol 104 shot:

Opportunity Heatshield, Filter L7

Its also another very good indiciation of the redness of the red planet. This problem occurs most often in the L7 (blue) filters. The sky is greatly more bright in blue than the ground or most any of the rocks that have been imaged...just a bit more evidence for the consistantly red features that dominate just about every image released yet.