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! :)
The art<span> of the </span>Renaissance<span> is characterized by realism. ... In the high </span>Renaissance<span>, from 1475 to 1525, artists including Leonardo da Vinci and Michelangelo focused on space and perspective to lend more realism to </span>art<span>.</span>