Thanks, I hadn't considered using a setup with photos/QR codes. Interesting. Definitely seems more secure than a thumb drive (although I think a thumb drive attack on an offline/encrypted wallet has got to be a really sophisticated and targeted attack).
It is true that such an attack is really really unprobable.
But i think this does not really always have to be a targeted attack.
IMO there is definetely a possibility of a malware (in this case: virus) which does spread itself onto thumb drives targeting offline storages without being directly targeted.
Sure, this sounds more like paranoia and won't happen to 99.9% of the people, but the possibility does exist (even though a very small chance of happening).