Random data looks patterned. Coin flips produce long runs, random walks produce trends and channels, and a random price series will show what look like clean support levels. Intuition treats these as signals because it expects randomness to look evenly spread.
This is why traders find patterns on any chart, including shuffled or synthetic ones. It is a useful exercise to try: mark up a randomly generated series and notice how convincing the levels feel.
The discipline is statistical rather than visual. A pattern earns belief when it has been counted across many instances with a control, not when it looks obvious in hindsight on one chart.
Related: apophenia, narrative-fallacy, hot-hand-fallacy, backtesting