You should have a by-law similar to model by-law 17 contained in schedule 1 of the Strata Schemes Management Act as follows:
Appearance of lot
(1) The owner or occupier of a lot must not, without the written consent of the owners corporation, maintain within the lot anything visible from outside the lot that, viewed from outside the lot, is not in keeping with the rest of the building.
It is a question as to how prescriptive you want to be as the whole thing can become a bit subjective. However, if the EC resolve that the owner is in breach of the particular by-law then you don’t have a problem – except to enforce it.
If there is still a problem with the owner then I would have a fire safety inspection, as that in my opinion, could be a bigger issue.