Not exactly the same thing, for one these aren't function calls, and for another the view is memoized: You can see the difference with some print statements:

    q)z::show(x;y;x+y);x+y
    q)x:42
    q)y:42
    q)z
    42 42 84
    84
    q)x:69
    q)z
    69 42 111
    111
    q)z
    111

Views are also aware of what's changed:

    q)a:1234
    q)z
    111
    q)y:69
    q)z
    69 69 138
    138

Well, you can do that in any language with first-class functions. But there's obviously a syntactical difference between a function invocation and a variable read.