What does the "Copy" button do?

The Copy button gives you 2 options:

Copy from day

This allows you to import a recipe from another meal slot. 

For instance, if you would like to have the same breakfast as you had on Monday, you just need to select "Monday", "Breakfast", and finally, "Copy". 

Copy to day

This allows you to copy the recipe in the existing meal shot to another meal slot either on the same day or another day.