This article is from the The Terminator FAQ, by Karsten A. Loepelmann firstname.lastname@example.org with numerous contributions by others.
This refers to the recurring imagery of humanity being crushed by the
machines. First, in the 2029 sequence of T1, there is a closeup of tank
rolling over human skulls. Next, when the Terminator approaches the house of
the first "Sarah Connor," it crushes a small toy truck. Also, after the
Terminator kills Sarah's friend, he walks over her Walkman headphones. In T2,
the title sequence starts with a Terminator endoskeleton crushing a human
skull. The imagery of the Hunter-Killer tank rolling over skulls reoccurs.
Terminator crushes one of the roses that falls out of the flower box when it
removes the shotgun at the Galleria (may be a reference to the T2 tie-in
by Guns 'n' Roses). The T-1000 treads on the Terminator's sunglasses at
Pescadero State Hospital.