1. Obsolete. A metaphor or parable.
2. An incidental reference, either directly or indirectly implying something.
3. The act or incident of subtle reference in a piece of art.
EX. Communication and interactions on line are unique because they can take so many forms, over such a long distance, and reach so many different/diverse audiences that no other forum of sharing has ever matched. The language of this communication relies upon metaphor and allusion more-so than any other form I've ever seen; as seen above, the images allude to Star Trek: The Next Generation, then a collage of popular meme imagery, then the "Mother of God" meme face (a reference to the film cliche where someone removes their glasses and says "Mother of God"), then the "Aliens" guy from the History Channel, before returning back with the conclusion of the images, that the internet is much like the alien race that Picard met in the TNG episode, The Children of Tama.
The reason that I found this neat little image series so amusing is that one of my high school Spanish teachers was a big Trekker (he even had a Klingon language chart hanging in the room) and showed The Children of Tama as a learning tool to describe the relationship between language and cultural references. Without a frame of reference, some parts of language are difficult to comprehend.
The episode was also one of my first exposures to TNG and well, as I'm currently on track to finish watching every episode of all Trek series by the end of the year, I'm probably grateful for the exposure to such a great program.