The "Thing" on Sol 328

(note: this is a translation of the Italian comment to images 1 and 2 herebefore) Watch out: the distance is different, the Martian Days (or Sols) are different, BUT the visual angle the 2 pictures were taken from is THE SAME! So what? So, we're now asking ourselves WHAT HAPPENED to the Opportunity's Heat-Shield in that lap of time running between Sol 104 (when this piece of "Space Junk" looked like a big sparkling stone, partly warped and partly squared - see the previous picture) and Sol 328 (when we "found out" that such a piece of metal was, instead, "round and tapered).
Maybe the "Aliens" - better yet: the Martians! - replaced the original "Made in USA" piece of junk with something else?
Perhaps the 'shooting capacities' of the Rover's cameras changed dramatically?
Or - maybe... - the People of NASA, wisely driven by wise minds, simply ERASED - as long as the Rover was getting closer to what we now believe it was a Surface Anomaly - the original artifact and REPLACED it with a "virtual" Heat-Shield?