I'm not familiar with the Obama Girl material.
Is it possible that it could be defended as parody, reporting or commentary?
If so, then the use of copyrighted material may have been legal under the terms of 'fair use'.
In the case of parody, the 'commentary' doesn't need to be directed towards the copyrighted work itself.
(Note that parody is not a use protected under 'fair dealing' in the UK. Fair Dealing is the comparable set of conditions to those defined under Fair Use in the US - with some exceptions.)
Oddly, in the US, the 'newsworthiness' of a newly created, infringeing work can sometimes be used to mount a successful 'fair use' defense.