It's just a car launch so the car does not look interesting, but it surely is no longer a low drag concept. Obviously Ferrari's Sidepod covering flow conditioners seems to be mainstream solution although it is important to remember that both Toro-Rosso and Mercedes raised their upper front wishbone to counteract the same problem(But it also required changing the suspension geometry for stability) so it will be interesting to see how many more teams employ Ferrari's solution to the larger front Tyre wake or will there be teams employing Toro-Rosso's version.
Williams version however is very simple and the Sidepod intake can easily be compared to the 2017-2016 versions although the same cannot be said for the Sidepod itself which has been on summer body diet and the intake itself is placed much higher to aid the flow-conditioners in front of it. Like the Haas and last year's Ferrari the mandatory side crash structure is placed in the flow conditioners and not in the Sidepods(Notice how thick the black section is). Also the deflectors like the Ferrari focus on moving the air around the Sidepods (Unlike Haas's version which almost solely focuses on pushing the air above the Sidepods and
relying on creating a "curtain" of vortices to minimise the effect of front tyre wake downstream while the large plate-like deflectors in the Williams
acts like the "Curtain" by itself. It's also why the Haas has a blown axle while the Williams doesn't need it(At least until the more downforce heavy circuits like Barcelona where Drag does not matter that much)*.
T-wings obviously exploit the allowed 650mm above the reference plane(Skid plate of the car)
This is the first car that gives a glimpse of the rear diffuser which in the Williams is very complex compared to the 2017 version. They clearly moved away from the smooth cut-off to the use of the gurney flaps as the outer wall thus showing they moved away from low drag concept(The 2017 Diffuser in the Ferrari was probably the most flawed concept as they tried to make a low Drag diffuser to produce more downforce which added more drag unfortunately which did work at low speed circuits but affected it's High speed cornering (
Not Medium speed, high speed like Silverstone, the car was fast in Malaysia)
2017 diffuser
* These airflow conditioners and deflectors are now one of the most complicated areas and different cars require different treatments to it depending on the flow coming from the barge-boards(Inner side of the front wheels), but at the same time it also have to minimise the effect of front tyre wake.
Great details in the launch car but sure for more to come (Like a Blown Axle for example)