Please describe the problem:
while copying a (video) file to an open nautilus window,
thumbnails are constantly updated/generated, this slows down copying
since video thumbnails take quite some cpu and read from disk.


Steps to reproduce:
1. open two nautilus folder, one with a video clip
2. copy video clip in the other folder


Actual results:
every now and than a thumbnail is generated for the new file.


Expected results:
it would be much better if a thumbnail would only be generated
once copying is finished.


Does this happen every time?
yes.

Other information:
i guess this also applies for other files, while with video clips the
problem is most noticable since copying takes longer.