First off, a hexagonal plot would help you to visualize this plot density much better.
To me, there is only one trend, the seemingly flat line showing the expected response as a function of the predictor. There is also an incredibly powerful issue of heteroscedasticity where points within the central portion of the predictors distribution have a MUCH larger variance.
Another way to view it is that the bivariate density of these two variables has a mode that's distributed compactly along the orthogonal (vertical and horizontal) axes of the plane. The "mode" of a distribution need not be a finite set of points, but could be said to comprise an area. But to my first point, I can't be totally sure of it when the points are swarming like squid in a black cloud of ink!