What is a pointed wing?
 

When pointed wings are subject to a positive angle of attack such that lift is generated, their tips stall immediately. That is to say even the smallest lift generating angle of attack will cause tip stall.

But what is exactly a pointed wing and how does it look like?

Any comments?

Any delta wing, or wing shaped like a triangle, has pointed tips.

Mirage fighters are a good example of this type of wing.

The reference from which you are quoting, may be talking about hypothetical pointed wings though - imagine a rectangular wing from an ordinary general aviation aircraft, that has been modified to have pointed tips.

Think of a Spitfire with pointy wingtips instead of rounded tips.

O8

Pointy wings
 

Pointy wings or tapered wings limit the bending loads on the wing. Typical of this design concept is the Stinson Reliant.

Helicopter blades have a negative twist to control the bending loads on the blades during flight for the same reason.

:E :E