No, this is not diffraction.

Let's start by recalling how the image is formed by the lens (focused and defocused):
![Focusing][1]


Each point of your large aperture lens contributes to just one point of the **defocused** image:
![Single ray in a defocused image][2]

*(by the way, this also shows why aperture size affects (de)focus)*



And what happens if you place an obstacle (your hands) near the lens?
Not all defocused rays can reach our image, as a result the image appears more focused and slightly shifted.
![Defocused image + obstacle][3]

And this is what happens in your photo - by covering the aperture, parts of the background become shifted and warped, depending on the obstacle shape.


  [1]: https://i.sstatic.net/tXRz3.jpg
  [2]: https://i.sstatic.net/ghTcs.jpg
  [3]: https://i.sstatic.net/2CYzR.jpg