I see no effective difference between the file's licence and the statement made by the author.
How do the attribution requirements differ? They are the same: the author is providing further information about what constitutes "appropriate credit", and also explaining that the text "from Wikimedia Commons" is not the same as providing a hyperlink to the file, which is part of the attribution requirements as given by the licence: "a URI or hyperlink to the Licensed Material to the extent reasonably practicable" is given at Section 3(a)(1)(A)(v). Most people do not read the licences in full so the author is reasonably providing some guidance.
Second: remix, transform, or build upon can all be satisfactorily summed up by "incorporate". Again, the author is simplifying the terms, but he is not making them more strict. If you reuse his image in any way, you must release your image under the same licence. Most people ignore this: he is drawing attention to it.
There is no incompatibility here.
Cheers,
Julie