.... Yes it could.

"It is not necessary that the plaintiff be designated by name; it is enough that there is such a description of or reference to him that those who hear or read reasonably understand the plaintiff to be the person intended." (citing Restatement (Second) of Torts § 564).

If their comments can be reasonably understood to refer to the makeup artist (i.e. by identifying the publication, article, photos, etc) it is cause for defamation. This does not mean that everyone who listens must be able to identify the person they're referencing. But, if any listeners reasonably understood episode to be referencing that makeup artist then this element is satisfied.

It's extremely difficult to win a defamation case and I'm not saying it's a slam dunk, but it is far from a frivolous claim.