Sidepod almost completely reshaped. Waterslides gone for the most part for a cleaner airflow at the top, while having a much bigger undercut. Reminds me of RB9 a bit, but with 10 years worth of advancements, bodywork is much tighter. They have also tightened the engine cover and have their own implementation of the Mercedes' "sausages". Not really to the same extent/effect that RBR and Merc have/had it, but similar idea.
Front-wing definitely looks different, but more comparison pics would help to see the difference. Same with the mentioned suspension changes.
Rear-end really seems like it's being treated differently though, especially the part in front of the rear brake ducts.