In order to find the answer, let's take a look at the pressure formula:
Since both women have the same weight, the force in the formula will be the same.
In the flat soles, the area where this force is distributed is greater, therefore the pressure felt by the women is smaller, which means the flat sole is more comfortable.
The area where the force is applied in the pointed heels is smaller, so the pressure is greater, which makes it less comfortable.