Pony tails..?

You look adorable!

@Killian_Joy  
Extrapolating on what Krypt said, its also because toast is one of the fastest things you can make for breakfast and eat on the run; With no-cook preperation items like yogurt or cereal you’d need a bowl or at least a spoon, the various other breakfast cooked/baked goods take longer to prepare.
 
My personal equivalent when I’m completely blitzed for time is to throw a sausage pancake (think corndog, but breakfast and far more delicious) into the microwave for a minute while I put on my shoes then grab it as I run out the door and get in the car. Theoretically for American breakfast items you might also have something like a donut which is pre-made, but people are less likely to have them on any given day than they are to have some sliced bread available.

Side note:
 

@Killian_Joy  
It implies the character is so rushed to get out the door that they don’t even have time to sit down and eat breakfast. It’s supposed to show that the character only just barely has their shit together in order to endear the audience without making the character a complete layabout.
 
It’s similar to when a character in american media runs out the door with shaving cream still on their face.

I was always confused by the toast trope, but this is adorable

Cute :3