I like to do these "gesture drawing" lines. You can probably find really similar lines with complicated maths, but these are not meant to be precise. The horizontal lines are just support and resistance levels. The lines slanted down are bearish trend lines, the lines slanted up obviously are the bullish trend lines. The purpose of doing this is simply another way to visualize price action. Like all charting.
Once in a while I find a line that wasn't immediately obvious but appears to have a type of gravity to it... in this chart, that is the yellow line. The way it contacts the top of the day 1 candle so perfectly, it reminds me of an old quote...
“Give me a place to stand, and a lever long enough, and I will move the world. ”
-Archimedes