Hi Jamus,
To begin with this new age of digital photography gives us a great means of communication. Thanks for your interesting pics
It looks as if the raven has simply vandalised the Euphorbia. I doubt if it would eat it. Also unlikely that it is searching for some particular tasty critta that lives just there. It reminds me of an event many years ago when some friends of mine prepared to open their gardens during a daffodil festival. They had wonderful drifts of daffodils in bloom. Along came the Sulphur Crested Cockatoos and beheaded the lot! Sheer vandalism! So back to your raven. Blackbirds create a mess because they fossick through mulch searching for insects but it does seem that the raven either hates or loves the Euphorbia.
One thing to consider is that we don't know what the raven actually sees. I believe that birds are able to see ultra violet light. Possibly the Euphorbia flowers 'glow' in a different colour spectrum which either attracts or annoys the raven.
Cheers, H:)