Magic: The Gathering XIII: What A Horrible Night To Have An Enchantment- Curse

[AgentPaper]

This actually isn't true. A Phantasmal Image of Ravager of the Fells can't transform at all, so when that ability resolves, absolutely nothing happens. A Phantasmal Image of Ravager of the Fells will never trigger the ability to deal 2 damage to an opponent and/or a creature, because it can't have ever transformed into Ravager of the Fells.

I think the rules explanation would be that the image can transform, it's just that being transformed doesn't do anything do it, since it doesn't have a second side. It still technically transforms, though, so it's ability triggers.