This filter adds a focal point, which is used in later transforms.
Normal Image:
https://push-3272.5centscdn.com/KB_IMG/Lights_5centsCDN.jpg
Transformed Image:
https://push-3272.5centscdn.com/KB_IMG/Lights_5centsCDN.jpg?im=500×0/filters:focal(146×206:279×360)