Carolina and NJ are constantly cycling back up high to see if they can make an in-zone rush from the blue line, as modern offenses like to do instead of just always going deep and grinding for chances from down low.
Each defends this by skating out to challenge and pressure. The Flyers under Tortorella strongly tend to sit back, yielding that space and hoping for chances to block shots, set up to defend chances from down low while their opponents aren't very concerned with dumping the puck in when they have room to work.
It's incredibly out of touch. Unbearably out of touch. Guy who doesn't understand offense anymore is also Guy who can't plan defense against it.