Round window on Wolfholm
The obvious part is Technic, Wedge Belt Wheel (Pulley) as Phil mentioned in the comments.

Other, not so obvious piece is Brick, Round 4 x 4 with Recessed Center, which comes in new Minions set. It only comes in Light Bluish Gray [BL] color at this moment.

Jonas has confirmed this over his IG post:

It's a Minion Eye.