Is the 'flexwing' back at Mercedes?

There was quite a buzz last season about the so-called 'flexwing', in which wings flexed up to a certain amount of degrees for more pressure. This ended up in a battle between Red Bull Racing and Mercedes. Mercedes brought updates to Spain this weekend and the question is now whether the flexwing will be part of it again.

During the third free practice session, a lap of George Russell was shown, where we rode along as it were. By looking closely you can see that a part of the front wing moves with the car as more speed is made. In the video below it is clearly visible that the left part is moving backwards.

Logically, this raises questions, because has Mercedes brought back the flexwing as part of their updates? And if so, the question of course is to what extent this fits within the regulations. This may also explain why Hamilton's front wing seemed to vibrate so much more than the other cars', which was seen during the third free practice session.