The backround picture of the tool should change every day, choosing the picture out of a pool of selected pictures. The attribution needs to change together with the picture. It should be possible to change the list of pictures easily, e.g. in some config file.
Pictures and respective attributions:
https://docs.google.com/document/d/1dmG524Qyb7VuBz2xzz04ds0bpaGiDPYgvs1t10D-cT
I/edit