I agree with bookishboy that Merc is not pretending to be a Brompton. It is clearly labeled and in some advertisements, Merc clearly distinguishes itself from Brompton. However, they are imitating the Brompton just like other companies imitate competitor's products.

From a layperson's perspective, the curved top tube and other Brompton characteristics seem to be closely related to function, so I am surprised that the copyright was enforced. If anyone has any information on the arguments/examples Brompton used in the Scoop/Neobike case, I would be interested in reading about them. If they changed the size of the fold or riding characteristics, then it would seem that the look is based on functionality.