Understanding an Algorithm for Singular Value Decomposition of a square matrix

First time user of the site, so I apologize if my question isn't worded properly.

I'm trying to implement the SVD of a square matrix using Algorithm 6 found on this website in C: http://ift.tt/1aRAc2M

Regarding the step where it says: "Determine d1, d2, c = cos(θ), and s = sin(ϕ) such that..."

In this step, what is the difference between the elements of the middle matrix? As in, isn't u2k,i the same as uk,i uk,i? (The top two elements in the matrix/the left two elements in the matrix)

If not, how should I be reading this algorithm?