Let $l_1$ and $l_2$ be two lines in $G(1,n)$, the Grassmannian of lines in n dimensional projective space.  
Suppose that their Plucker embeddings has dot product zero. Namely if $(x_1, x_2, \cdots, x_N)$
and $(y_1, y_2, \cdots, y_N)$ are their Plucker coordinates, $\sum_{i=1}^N x_i y_i = 0$.
Is there anything special about $l_1$ and $l_2$, e.g. are they necessarily orthogonal to each other?