I'm working on a book. Say I include a single unmodified work in the book that's licensed under Creative Commons-Attribute-Share Alike, for example one picture. Do I have to make the entire book CC-BY-SA if I do this, or not? Followup: what if I modify the picture? Does the whole book have to be CC-BY-SA, or just my modified picture?
Any adapted work derived from a work used under a CC-BY-SA licnese must be distributed, if at all, under a compatible license. The question is whether a large work incorporating a much smaller work is said to be "based on" that work. The CC-BY-SA 4.0 legal text does not use "include" or "incorporate" or any similar term to define an adapted work, instead it says:
Adapted Material means material subject to Copyright and Similar Rights that is derived from or based upon the Licensed Material and in which the Licensed Material is translated, altered, arranged, transformed, or otherwise modified in a manner requiring permission under the Copyright and Similar Rights held by the Licensor. For purposes of this Public License, where the Licensed Material is a musical work, performance, or sound recording, Adapted Material is always produced where the Licensed Material is synched in timed relation with a moving image.
If including a single work makes your book Adapted Materiel, than you must either release the book under the same license, or else not rely on the CC license. I am not at all sure if such use would make the book Adapted Materiel.
If the content could be quoted (perhaps only in part) based on fair use or fair dealing or a similar theory, you would not be relaying on the license. But whether such use is legitimate is always a very fact-bound question, which will depend on various specific facts. See Is this copyright infringement? Is it fair use? What if I don't make any money off it? for a summary of US fair use principles. If the materiel you want to use would not qualify under fair use (or whatever similar principle applies in your jurisdiction), and the book would be considered Adapted Material, then you would have to omit it or put the book under the CC license.
I see in The CC case law page the statement that:
The atlas was a compilation not a derivative work, so did not need to be licensed under the SA term,
Which might apply to your book. If it does, you would not need to place the book under a CC license.
On reading CC's detailed wiki page on Drauglis v. Kappa Map Group, LLC I find the statement that
Use of a whole work is suggestive of a "compilation" rather than a derivative work subject to the ND/SA terms.
attributed to the US District court (DC circuit) that decided this case in 2014. If that decision were followed, it would seem that the book would not be considered a derivative work and while proper attribution must be provided, and the applicable license must be indicated, the book itself need not be released under CC-BY-SA.