In the left-hand window, WP represents a point in "portfolio space", that is a set of three weights that add up to 1.
You can move WP to see what happens in the risk-return window on the right.
The point P corresponds to WP and has an associated bullet for the combination of P and the tangency portfolio.
You can show or hide the value of beta that corresponds to P.
Can you see a relationship between P and beta?