I believe that was changed with the release of Revelations of John.
There was much discussion about how to handle that identifier, but the decision was made that "depicting an idol" was too subjective (after all, objects like the sun have been worshiped as idols so then any card with a sun in the image would "depict an idol.")
For the sake of simplicity, it was decided to make "depicts an idol" the same as "is an idol." While this might lead to a bit of confusion with a few cards (such as Abom as you mentioned), it will ultimately make things easier as we move forward since we're not using that phrase on any new cards.
