How to interpret the divergence of a vector field plot at a point.

Question

I've a vector field given as:

$$ \vec{F_{(x,y)}}=sin(x) \hat{i} + cos(y) \hat{j} $$

It's divergence $\nabla . \vec{F_{(x, y)}}=cos(x)-sin(y)$

I've a plot of a vector field below:

Note that the ranges of values on x and y are in radian from 0 to 180. I've taken 20 points in that range.

Now, here comes my question

At a point ($\pi$,$\pi$) though this point is not a sink, why is the divergence negative at that point.

Same applies for point ($\pi$, 0)