It has nothing to do with the task.
What's Actually Happening
Bluma Zeigarnik demonstrated in 1927 that uncompleted tasks occupy active mental space in a way completed ones don't. Your brain keeps an open loop for everything unfinished - a background process running quietly, consuming resources, generating low-level friction.
Zeigarnik effect (overview)
A task you've delayed for three days doesn't just take 2 minutes anymore. It takes 2 minutes plus the weight of three days of not doing it. Every time you saw it on your list and moved past it, your brain logged a small failure. The task is now carrying that history.
This is why the delay makes it worse. The task didn't grow. Your relationship to it did.
Timothy Pychyl's research on procrastination confirms the mechanism: avoidance is self-reinforcing. The emotional discomfort of not doing something becomes attached to the task itself, so approaching it now triggers the accumulated discomfort - not just the original mild friction of a 2-minute job.
Pychyl, T.A., & Sirois, F.M. (2016). Procrastination, emotion regulation, and well-being. In *Procrastination, Health, and Well-Being*