The closest thing that I can say among all of these answers would be improvisation. The definition of improvising is adapting to the situation in a better manner appropriately. So let's say when a musician is already on stage and makes a mistake while playing the guitar, he has to improvise a bit so that his mistake will not look like one. He is spontaneously creating something while he is on the spot. In a sense, he is improvising his original work and making something somewhat different.
Answer:
Well, I don't have an answer but I need points (asking for a friend)
The first one can be seen either way. For me, I saw a vase first. In all of the pictures, the black drawing is considered the positive space and the white background behind it is considered to be the negative space. If you look at the vase picture again and imagine the background to be the black portion, you see two faces.
Hope this helps! :)