There is no guarantee that it will always be like this. In general, implementors maintain a literal pool maintaining each of the string literals only once, and then for multiple usages of the string literal the same address is being used. But one might implement it a different way - the standard does not pose a constraint on this.
Now your question: You are looking at the content of the two pointers pointing to the same string literal. The same string literal gave rise to the same value (they decayed into a pointer to the first element). But that address is same because of the reason stated in the first paragraph.
Also, I would emphasize providing the argument of the %p format specifier with the (void*) cast.
