Just like the FW36 render there are things that will evidently change before the season kicks off but there are a few things we can learn from what has been shown.
You may note that the sidepods appear to be a little slimmer than the cars predecessor allowing for a more aggressive sidepod undercut, the team having seen the packaging potential of the W05 have opted to run a chargecooler (air-liquid-air) arrangement, burying the cooler within a void between the fuel tank and the ICE's front face, whilst balancing the aero for either sidepod with smaller water radiators (Rather than as last year having had the right sidepod carry the engines water radiator and the left an air-to-air cooler).
Lastly and perhaps more importantly (but please remember this a theory and not fact and so I am not inferring any wrong doing by Williams or any other team) I have to raise the question of flexibility, especially when we consider how quick the FW36 was in a straight line compared to the rest of the field. I've long held the opinion that some of the teams are using aeroelasticity to deform the rear wing assembly in such a way that it reduces drag on the straights (something that teams have been doing for decades). Williams lack of centre pylon brings further credence to this (albeit as per the FW36 they likely have a beam wing support at floor level again) as it would allow the endplates to deform/rotate (where as everyone else would also need a deformable pylon too) lowering drag and increasing their top speed potential. There is of course a load test in place to ascertain whether teams are flexing the flaps (a horizontal load of 100kg on the FIA inspection rig), meanwhile slot gap separators were bought in so that the teams couldn't deform the flaps at speed, reducing the gap between them and stalling the wing.
As teams have worked on aeroelasticity to gain advantage from front wing flex over the last decade it's more than acceptable to expect the teams to use this knowledge in other areas, in which case if the rear wing was lent back under load it would reduce drag. Lest we forget the teams desires to achieve such a feat led to the F-Duct and a top speed increase in the realms of 10+kph.
As always please remember that this is a very early look at the car and as some of the key areas (rear view, tyre squirt platform ahead of the rear tyre etc) are omitted in these renders I will revisit the analysis as and when more details become available.