Curiosity got bored with the piece of plastic that apparently fell off it, likely after being dislodged during the landing, and is back to playing in the sand.
The Mars rover already had a scoop-full of sand and was planning to give some of its mechanisms a test run and a clean up, by processing the sample, partitioning it for further analysis, and moving it through its internal piping.
The idea was to do this two times and only pass the sample to the internal instruments on the third and fourth scoops, to make sure there's no material from the trip or, worse, from Earth, contaminating the samples.
Curiosity is now processing the first scoop
, but may resume its analysis of the piece of plastic after it finishes with the first scoop and starts the second.
After it's done here, Curiosity will be heading to a close by location to test its drill for the first time.