Layers and Time are important aspects in design.
Nothing is ever perfect on the first try. There is always something that can be improved upon or refined. As they say Rome wasn't built in a day. Every good design was endlessly worked on. You can go back an experiment with what could improve the piece. Also, when you stop thinking about a certain project for a while, some things can pop up at you and inspire to think differently. Oftentimes, you have to step out and be critical of your own work to understand what can be improved upon.
Layers are a way to improve upon a piece and make it intriguing. During our Installation election, what our first iteration looked very different from the last iteration. Also, each iteration had a different meaning to it. The first week, we were trying to capture the facts and accomplishments between the two. The second week, we were showing all the negative aspects to the campaign and the third week was simply relaying a message within our work. It doesn't have to be complex. Because the election was still going throughout, our feelings towards the election changed. This is how time and layers interacted with each other.
Examples