Student or Learner
If you see someone in the flesh, you see someone ..... you previously had only seen in pictures, films etc. (who OR whom? )
Whom (Because of referring to the object!)
It's fine, but most people would use who.
Don't we use who for referring to the subject?
Yes, we do, but most people also use it for the object. Whom is mostly found in formal language. In speech, very few speakers would use whom in your examples. Some would write it, but most wouldn't.
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