Snowden himself mentioned the difference between his actions and Manning's. Seriously, go read the interview.
However admirable Snowden may have found Manning's principles, he demonstrated a much different of Manning's actions when he explained his decision to leak what he did.
To agree, and explain what you'd find in the interview:
He practically criticized Manning when he described how he went about preparing the release. There was no reason for him to talk about the meticulousness with which he chose what to leak except as a contrast to Manning.
