more information, that's good.
your pattern wants you to do short rows
there are videos explaining that really well, like this:
(on this page I only find short row with wrap, which is not what your pattern calls for).
so, basically, it wants you to work to that point, just turn your work around and work back to where you came from, mid row.
you do this as indicated in the pattern.
what happens is that you make one section of your knitting higher than the other. that can be one side, or the middle, or anything... you know?
your knitting takes shape by that and does not remain rectangular.