[aerohead]

In Wolf H. Hucho's 2nd-Edition, he had a schematic rendering of such a feature.
It had to do with yaw-moment in crosswind and gust.
If memory serves me, in zero-yaw flow, the leading edges will provide for full flow attachment, since it's all in a favorable pressure gradient, moving towards low pressure.
In quartering crosswind, or gust, the structure acts as a burst edge, to force separation, which, otherwise, might allow bistable 'hunting' of the air beyond the nose, and potential stability issues from a larger, low leeward pressure- induced understeer.
I don't have my book with me. We'd want to double-check.