Struct with array member in C

Recently I reviewed some C code and found something equivalent to the following:

struct foo {
    int some_innocent_variables;
    double some_big_array[VERY_LARGE_NUMBER];
}

Being almost, but not quite, almost entirely a newbie in C, am I right in thinking that this struct is awfully inefficient in its use of space because of the array member? What happens when this struct gets passed as an argument to a function? Is it copied in its entirety on the stack, including the full array?

Would it be better in most cases to have a double *some_pointer instead?