Divertimento (2) : a Clue…

Welcome everybody….
So, yesterday I posted “Divertimento”…A little game for all of you that check my blog from day to day …
The question was…What is this? Where are these “Ghostly dancers” coming from?
Seems to be iIt suggested almost the same thing to all of you: wash line, clothespins…
Well…It is not…
But it has something to do with lines…And something to do with trees…
And here is another clue…

Ghostly dancers become “Ghostly butterflies” when looking at them from further away….
ghostly butterflies

ghostly5

Tomorrow the answer….:)