Optical Illusion Art VIII

I am sorry if you thought I was through posting on this subject; that was an illusion. You may be pleased to know though that this is the last one. At least it is for the moment; unless and until I may come across something to complement these posts.

This optical illusion has two tricks up its sleeve:
1. If you stare at one block, it seems like the other blocks are sliding.
2. When you look at the gray lines, are they straight or bent?

In the first case; none of the blocks are moving, but you probably had already figured that one out. In the second case; it may be hard to believe, but the gray lines are perfectly straight.

Here is a bonus one for you:
:-D
Do you see a smiley face in that? Actually, they are nothing but symbols on your keyboard, but your mind reads them as a smile. Grin.