What's the issue?
The wording of CC BY-SA licenses changed significantly between versions 3.0 and 4.0, but I don't believe Creative Commons (CC) intended to narrow the scope of share alike (I explain why later). When I read the licenses, however, it seems to me that the scope has narrowed, which makes me suspect that my concept of what the scope is for either 3.0 or 4.0 is wrong.
In this question, consider an example where someone uses several illustrations released together under a CC BY-SA license to create a book. The illustrations are completely unaltered; the author simply places an illustration on each page with some separate (but related) text to create the book.
Different scope between 3.0 and 4.0 licenses
Under a CC BY-SA 4.0 license, I believe the author is not required to release the book itself as CC BY-SA (or equivalent), so this is out of the scope of the share-alike clause.
To paraphrase the 4.0 license legal code, for the book to be Adapted Material, the book must be based on the licensed work (which is the case) and modify the licensed material (which has not happened). Only Adapted Material must be shared alike, therefore this is not required to be.
This argument for 4.0 appears to be agreed upon in this question.
Under a CC BY-SA 3.0 license, I believe the author is required to release the book itself as CC BY-SA (or equivalent), so this is within the scope of the share-alike clause.
To paraphrase the 3.0 license legal code, for the book to be an Adaptation, it must be based upon the work (which is the case) and not be a collection (it's not a collection - see below). Adaptations must be shared alike, therefore this is required to be.
A collection must include work in 'its entirety in unmodified form' (which is the case), 'along with one or more other contributions, each constituting separate and independent works in themselves'. The only other contribution is the added text, which is not independent from the images since the images are chosen (or text is written) so that they go well together.
Why the scope shouldn't have narrowed
CC explicitly state here that the scope of share alike hasn't changed, and state more generally that adding a clarification to narrow the scope of adaptations would 'abuse the trust of licensors' (see end of point 2 and point 3 in the ShareAlike intent document).
Yes, the wording of the licenses have changed significantly, for example, in 4.0, there's no explicit mention of collections, but this is presumably due to the specific aim of 4.0 to make the license internationally applicable and easily understood. CC state here, for example, that not explicitly addressing collections 'does not change the scope of the license or the ShareAlike term'.
Have I got the wrong impression of the scope for 3.0 or 4.0, or is it actually that the scope of share alike has narrowed?