Both Williams and Renault had complex wings for the low drag demands of the Canadian GP. In Williams case the wing is shaped to create most downforce in its centre, leaving a much shallower span near the endplates. This design reduces the pressure difference where the wing meets the endplate. This reduces the vortices produced at the wing tip and hence drag. Although the Williams wing is fitted with DRS, low drag is still critical as DRS can only be used in the race in the situation where the car is less than 1s behind another at the DRS detection zone.
Renault meanwhile have twisted their rear profile to match the oncoming airflow. This is in fact an old wing already seen in 2010.