Judge on a single sample, do you ? :) That's a fairly strong statement based on a fairly small dataset :( But yeah, our heuristics to ignore some content (e.g. websites screenshots) sometimes trip on real pictures. There's still a lot of room for improvement :)

Judging by the tags, it recognizes this as a street sign (which is great and amazing), and yet says it's "not a photo".

A photo of a street sign is definitely a photo ;-)

https://keegan.regaind.io/p/v5bCFkeRRYSvendxCM73yA

Yeah it's super harsh with street signs or that kind of large text on pictures. The protection is there to avoid saying really silly stuff on utilities bills and other kinds of paperwork. I'll add this example to the ones we should accept.