My colleague and I really favor the twentythirteen's circle.png and thus would like to use it in our temporary namecard. Although we don't change its basic design, we have to trim it a little in order to have the image fit into the card. And because we really like to conform to whatever legal and moral in the opensource work, I searched a bit and found that:
- I haven't found any license and copyright from twentythirteen declared.
- I found this web page #1 that says wp's themes are GPL.
- The same page also states that the images in the themes don't fall under GPL.
However, theoretically, the only derivative work that falls under GPL is the PHP code; any images, CSS and other content in your project remain yours. On top of that, you are free to charge extra for technical support and so on.
Question: does our usecase described above work?
I'm interested in my particular usecase first, but I'd also appreciate general cases if anyone could provide answers for it.