Reflection or illusion or both?

Having been out and about for the last week i returned to the office today (first mistake)

The second mistake was failing to get out for lunch so no outside blip.

In desperation I lifted the venetian blind in the glass box and discovered to my amazement that there was light, sun and an interesting blip.

If you get the timing right and the wind is in the right direction you can even get reflected planes going into Heathrow but I wasn't quick enough!