Non-defined function parameters used as local variables

My question is about understanding a design pattern I encountered here.

Basically, we have the following IIFE:

!function(param1, param2, one, two, three) {
    // do something usefull with <param1> and <param2>...

    // ...and use <one>, <two> and <three> as local variables
    one = function(...) {...};
    two = 123;
    three = document.createElement(...);
}(value1, value2);

One can see that some of its parameters are used as local variables only. They are undefined when the function is called.

Are there any differences with the (more readable) code below?

!function(param1, param2) {
    // do something usefull with <param1> and <param2>...

    // ...and use <one>, <two> and <three> as local variables
    var one = function(...) {...};
    var two = 123;
    var three = document.createElement(...);
}(value1, value2);