In a vertical arrangement there is only one column, so there isn't really a left or right. Second from the top would be the directly under the top, second from the bottom would be directly above the bottom.
Given a set of items:
[A, B, C, D]
A is the leftmost, B is second from the left and also third from the right, C is third from the left and second from the right, and D is the rightmost.