Position feedback - my element inside at element

[mburisin]

When positioned element is inside target element, the position numbers are calculated correctly, however feedback is calculated incorrectly when my, and at parameters are set to same value.

For example:

my: "left bottom",
at: "left bottom"

and

my: "right top",
at: "right top"

are giving feedback

horizontal: "center", 
vertical: "middle"

With different values, it gives the position correctly

my: "right top",
at: "left bottom"

gives

horizontal: "right", 
vertical: "top"

CodePen here: ​https://codepen.io/anon/pen/ZopvXL#anon-login

EDIT: I'm getting some weird behavior in many cases and I can't understand very well what horizontal & vertical feedback values mean. Maybe behavior described above is not incorrect and it works as intended. Would be nice to have explanation in documentation what these values means and how are they calculated.