On page 2, panel 3, a block of concrete in the rubble has the number 231068 printed on it. It was also seen on a block  in "Suicide Mission" on page 11, panel 1 and will be seen yet again in "Father's Day" and "The Programming of Fate"; it represents artist Gary Erskine's birth date, 23 October 1968.

Also on page 2, panel 3, the walking Hunter-Killer seen here is based on pre-production art from Judgment Day of an HK known as a Centurion.
Centurion from this issue	Production art of Centurion (from the Terminator Wiki)

On page 2, John Connor's narration mentions scurrying land mines called Silverfish. These were another type of killer built by Skynet that was developed in the pre-production of Judgment Day, but was not realized for filming.

Page 4 gives us a glimpse of John in command of worldwide forces in the final battle against Skynet, as stated in the novelization of The Terminator.

On page 6, a block of concrete in the rubble has the words "Liz Phair", "Whale", "Curve", and "NIN" scrawled on it. These are all rock bands started in the late '80s-early 90s. "NIN" stands for Nine Inch Nails.

On page 10, one of the resistance soldiers that helps carry the T-800 endoskeleton into Danny's lab has a name badge on his uniform that says Van Ling. This may be a reference to the man of the same name who has done visual effects work on several James Cameron films, including Judgment Day.

On page 11, Danny refers to the Terminator skull as Rusty.

On page 15, two T-1000 models are seen in the Skynet complex. One is implied to be the one that will travel back in time to terminate John Connor. This issue states the time destination as 1994, though it should be 1995 since John is said to be 10 years old in Judgment Day.

On page 18, Jude holds up a cheap copy of the famous Sarah Connor photo. This is a copy of the same photo that Reese brings back with him to 1984 in The Terminator. The novelization of Judgment Day reveals that many men have paper copies of the famous Sarah Connor photo that they carry with them for inspiration. Reese has the original, as given to him by John. 

On page 19, Raphael refers to a WM-25 forty-watt phased plasma pulse-gun. This is presumably a reference to the Westinghouse Model M-25 phased plasma rifle described as carried by many future human resistance members and Terminators in the respective novelizations of The Terminator and Judgment Day.

Also on page 19, a squad of resistance soldiers inadvertently attempts to ambush the reprogrammed T-800 of Omega Platoon. One of the squad members is called Simmons. It's unknown if this Simmons was any relation to Greg Simmons, who, along with Jack Kroll, is said to have discovered the Terminator remains in the factory at the end of the novelization of The Terminator, and who later becomes the owner and CEO of Cyberdyne from his discovery, as revealed in the Judgment Day novelization. There is also a Simmons in the resistance in From the Ashes; possibly, he is the same person seen in this issue.