In so doing they are apparently following NASA’s lead which has traditionally made photographs available in the public domain.
Motherboard reports that SpaceX originally used an Attribution-NonCommercial licence but later removed the NonCommercial requirement, so that they can be used by anyone for any purpose, as long as the source is credited.
In a tweet, Elon Musk claims to have made the images fully public-domain, which means that they could be used without attribution. However Flickr still lists them as CC-BY.
@Pandoomic Just changed them to full public domain
— Elon Musk (@elonmusk) March 21, 2015
In fact, Flickr’s terms of service do not provide the option to make images public domain. If SpaceX want to do that, they may need to host them themselves.
So, with credit given where it is due, here are some beautiful pictures: