Let us take a simple example that we get to see often in our games.
Beastmaster has a level 6 power spike. With a hero like Lina, the moment he has level 6, the safelaner is in big trouble.
Phantom Lancer also has a level 6 power spike. It will allow him to go to the jungle and dodge the Beastmaster’s level 6 power spike. This whole laning stage is all about who is going to hit level 6 faster.
Phantom Lancer should ask his position 5 to stack and pull the small camp to deny as much EXP as possible while he leaches the minimum amount of exp. At the same time, he should also give the call to block the big camp. For example, suppose Beastmaster gets to level 6 before Phantom Lancer. In that case, he will most likely kill him or force him to go to the jungle at level 5, which is slow and ineffective.