Greased paper window

Okay kiddo, imagine we have a piece of paper with some special stuff called grease on it. That grease helps things slip and slide around. Now imagine we put that greased paper on a window, so we can see through it. But something weird happens! When we look through the paper on the window, everything on the other side looks all wiggly and wavy. Why does that happen?

Well, when light tries to pass through the greased paper, it gets all bent and twisted around because of the grease. It’s like when you put a straw in a glass of water and the straw looks like it’s bending. So, when we look through the greased paper on the window, the light that travels through it gets all bent and wavy, making things on the other side look distorted.

This is why we call it a "greased paper window" – it's like putting a special filter on a window that makes everything look wiggly and distorted. It can be fun to look through for a little bit, but it probably wouldn't be great for looking at things like pictures or trying to see clearly.