All images, assets and vectors published on unDraw can be used for free. You can use them for noncommercial and commercial purposes. You do not need to ask permission from or provide credit to the creator or unDraw. More precisely, unDraw grants you an nonexclusive, worldwide copyright license to download, copy, modify, distribute, perform, and use the assets provided from unDraw for free, including for commercial purposes, without permission from or attributing the creator or unDraw.
It looks good to me. For a novice like me, it seems quite open.
This license does not include the right to compile assets, vectors or images from unDraw to replicate a similar or competing service, in any form or distribute the assets in packs or otherwise. This extends to automated and non-automated ways to link, embed, scrape, search or download the assets included on the website without our consent.
But I am skeptical regarding this. It seems individual images can be used and redistributed as anyone wants, but the collection of images as a whole cannot be redistributed at all.
Is it even possible to have a license regarding the collection of images that is different from the license of each individual image, and even "supersedes" the sum of each file's license? Would such a thing be acceptable regarding to the OSI definition, or to Debian's DFSG?