Not quite, in this analog world with ramps and delays and even hysteresis.

A toaster -- let's be clear here since the English Muffin was brought up -- a two-slice (the slices are vertically oriented) toaster pops up when an element inside the toaster reaches a particular temperature. You can verify this by trying to push it back down right away; usually there's a buzzing sound if you hold it down and the toast just pops back up. If you move the lever to a higher number, the toast will stay down. If the room is a lot colder than normal, the toast will stay in just a tiny bit longer.

So it's heat causing something to reach a temperature that pops up the toaster.

But it's heat above room temperature, and it takes some time to reach whatever temperature will release the bread.

Sure, the heating elements are at full blast almost right away, but there's no actual timer in a toaster like that.

Hysteresis comes into play when you want to toast two more pieces and you try to do so right away.