That is not a Marble Queen (even if it was labeled that way) That looks to either be a "Manjula pothos" or an N' Joy Pothos.

Thank you, yes I do realise they put different name for this plant, in Australia they named it Marble Queen everywhere.

So what do you think the cause for the deformation and relatively small leaf?

That is not deformed. That is the way this variety grows.

Google the names massey gave and you will see your plant, with leaves just like yours. It is not a marble queen, although there certainly are too many names for this plant right now.

Thank you :)