A video is described as a subliminal message because it does not name anyone.
The absence of a name here concerns the ambiguity of the recipient, it does not demonstrate a subliminal mechanism. I propose to use more precise words: allusion, implied or indirect communication.
In the example, this distinction avoids attributing unverified hidden power to the post. Accurate language makes it possible to discuss the effect of communication without turning any misunderstanding into scientifically proven manipulation.