This is a stippled version of Grace Kelly (circa 1954 Rear Window) using 2000 dots. This was the most complex print created using an untethered quadrotor for the paper "Stippling with aerial robots" published at Computational Aesthetics (Expressive).
Stippling with aerial robots project page for the publication at Computational Aesthetics / Expressive.
The supplementary video for the conference publication, showing time lapse videos of various portraits being created. A time lapse of the creation of Grace Kelly, with the video taken from above, can be seen at the 2:12 mark.
This video produced by the McGill University newsroom provides a high level overview of the project.