"Today we can see the first glimpses of our workspace," - Bruce Banerdt, InSight Lander's Principal Investigator.
"We did extensive testing on Earth. But we know that everything is a little different for the lander on Mars..." - Tom Hoffman, InSight Project Manager at JPL.
Sources:
NASA Press Release: NASA's Mars InSight Flexes Its Arm
NASA: InSight Mission Overview