One curve is the inflow performance, rate against flowing bottomhole pressure. The other is the outflow: the bottomhole pressure the tubing needs in order to pass that rate up to the separator against the wellhead pressure. Plotted on the same axes, they cross at the operating point. That rate is what the well will do.
Move the choke, the lift method, or the tubing size, and the outflow curve moves. Deplete the reservoir or damage the completion, and the inflow curve moves. The crossing is the whole point of the plot. A design that quotes an inflow rate without the outflow, or a tubing capacity without the inflow, is not this analysis.