I read the books. They basically did something similar with higher dimensional stuff in Inception although that was toned down but the idea is that you could see everything at the same time. A 4-d being or object in 3-d space would be pretty easy. Imagine a tiger but made up of floating 3-d droplets with space in between those droplets. That’s one interpretation of how a 4-d thing would appear to us. Although there is basically none of that in this book series.