How to programatically change image style of images gathered by view?
You could try a different approach, via the Views UI, adding the same image field 3 times, and assigning each of these different image styles. 

Add a View result counter field, this will let you know the row number.

Then on template/twig file print image field that was assigned x image if counter (this is the twig variable name for View result counter) equals y.