By taking a look at the 2016 vs 2017 car, we immediately notice a change in the rear wing (1). It's lower and wider, much like everything else on the car. The tyres (2), overall width (3) and front wing (4) are all stretched out to make the car faster and look more aggressive.
Although much the same from the back, it really showcases the change in the rear wing (1/2), as well as the difference between tyres (3). Another change is that the rear diffuser's permitted height, has increased from 12.5cm up to 22cm (4).
From this angle, we can see that the nose of the car (1) has increased by 20cm compared to 2016. The overall width of the car has also increased from 140cm to a maximum of 180cm (4). The car however, cannot be 180cm for the entire length of the car so there must be a cut-out (6/7), but the cut-out cannot be more than 10cm deep.
Finally, from the side angle you can see a visual change of the nose and front wing (1/2). The large tuning vanes (3) will help direct airflow and it showcases the larger and lower wing (5) that will help create more downforce.