What is the name of the renaissance art style whereby objects are viewable when looking from side of frame?

I'm thinking of items like Holbien's "The Ambassadors," where a skull is only clearly a skull when seen from the side of the painting. But that's the only painting I can think of. I would like many more examples. If you know examples or the name of the genre, or most especially some documentary about them that I could YouTube for my daughter, that would be great.