Reflection explanation required

[zulu Delta 534]

Sitting in our backyard each afternoon around 1730-1800 or so (God's time), the sun has set, or is setting in the west (behind us) and we look across towards the East, at our neighbour's shiny new colourbond roof and we are greeted by this inverted "V" shaped shadow/reflection on the roof.
I guess it has something to do with the corrugations of the roof material as it is only visible when the "Whirlybirds" are viewed in line with the corrugations.
There are street lights situated to the east of the roof but these have not come on at this time of night, nor do they correspond with the angle of the reflections/shadows.
I can't seem to come to grips with the "whirlybird" having a circular base, hence an everchanging angle of incidence to reflect any wayward light rays from, and the reflection not corresponding with the reflective item.
My question therefore is; "Why am I seeing the inverted"V"?"
Any logical answers sought.


Hope this makes sense to someone!
Regards
Glen

[JDNSW]

You are seeing the reflection of the ventilator in the corrugations of the roof - because each corrugation covers a wide range of reflection angles you can see the reflection on both sides of the ventilator - on the LH side it will be reflecting from a little bit to the left of the bottom of the trough, and vice versa. The reflection is, of course distorted by the corrugations. The light background is the sky reflection.

John