Choice between patterns

As I understand it we can use (at least) two patterns to define a shape 
for a class. Using the examples in the specification we can declare a 
shape for the class ex:Person either by directly declaring ex:Person as 
type sh:NodeShape

ex:Person

*a *rdfs:Class, sh:NodeShape .

or we can declare a nodeshape class that use sh:targetClass with 
ex:Person as object

ex:PersonShape

a sh:NodeShape ;

sh:targetClass ex:Person ;

What would be the implication of each of these two patterns?

Are there any pro and cons to the two?

In which situations should I choose the first instead of the latter?

Regards,

Peter