Your BFF must feel happy if you bring her your homemade lunchbox. It's not just putting all food ingredients together. It shows your deep affection. You can play the challenge mode to fill your lunchbox in due time. Or you can play free mode to create your own. Have fun!
A context menu should be shown when right-clicking or, on touch devices, long-pressing in the game. This menu especially allows to play in full screen and control the volume.