It's time to build a UI for our DApp. We're going to build an HTML/CSS/JavaScript page which will display the pixels that we have on the blockchain.

Keep this in mind: what we're building is a visualization of the true data that exists on the blockchain. That is, our page isn't the source of truth, it's a visualization.

This means that this app could run locally on anyone's computer without connecting to the broader Internet as long as they have our code and the Ethereum blockchain on their local machine.