I have an array of objects that contains the real face and an array of posible fake faces, each item of the array is another object with the face and if its fake or not.
Then i take a random item of the first array as the real human and i take a random item of their posible fake humans and when the player click a button, i compare if their comparison is an alternate or not.
Also i said randomly but i just make a new array an fill it randomly with the faces database, then i go one for one, that way there´s no repeat.
The rest its CSS