yeah i was thinking about that too
can someone smarter than me explain if that's necessary at all or if it's just to make people download adware/malware/whatever?
Processing the pictures takes processing time, as it's not actually done on googles servers, it's done on their server using google's deep dream code. Their server can only process so fast, so if they have more computers processing things it goes faster for everyone, and as a bonus incentive if you have pictures you want deep dream'd, if you contribute your images get fasttracked.
They give you the chance to run, in a secure sandboxed environment (a fancy term for "sealed-off from your computer") that cannot give you malware, what they run, so the results are the same.
