Can someone clarify this for me? From watching their video, it seems like all they've done is build a tool that visualizes DNA? I don't understand how the tool

Can someone clarify this for me? From watching their video, it seems like all they've done is build a tool that visualizes DNA? I don't understand how the tool assists with visual differences in DNA. I expected maybe a single DNA sequence in one color with the differences highlighted in a contrasting color. Maybe the video just didn't do a good job of explaining things.