While it definitely resembles an iMac, HP has been exploring the post-mouse era a bit with their Touchsmart series, and this could be seen as a cousin to that brand.
I think that’s exactly what makes this so strange. HP already was selling all-in-one PCs that did not look like iMacs at all. They could have continued with that – but for some reason decided not to.
In fairness to HP, the Touchsmart line is terrible. Bad build quality, BSOD's on first boot, awkward design decisions, atrocious touch experience, and literally forty preinstalled and thoroughly rotten "touch" apps that join forces with dozens of sludgeware packages to make the first hour of use punishing. The Spectre looks like a work of art compared to them.
(By awkward design decisions: there's a secret chamber that holds a secret USB port that's already got a secret USB stick in it that drives the radio for the included wireless keyboard and mouse)
That's where we disagree, looking at these it's a completely unfair distance away from an iMac (read: way too close to even slightly think it's not a design copycat game)
There are designers out there that know how to put both original and great designs: [0] is my keyboard and mouse at work. [1] is good design, except the front begs for a 4:3 screen (which would make it gorgeous) instead of that 16:9+big block below. [2] shows how good artists steal instead of copy.