Word for many people doing the same (silly) thing

An example: Tourists at the leaning tower of Pisa all doing the same (clichéd) pose.

Is there a single word for such behavior? It's not a flash mob, obviously, because it happens all year 'round. It's not mirroring because it's not subconscious behavior, but something very intentional. It's not synchronicity because it's not a spontaneous thing. It's not aping or copycatting either, since people aren't (necessarily) mimicking anyone in particular.

I suppose it's ritualistic, but that seems too serious for something so silly.

I suppose this behavior constitutes a meme, but I'm wondering if there's a better word for it. Or for the act itself; the act of participating in and propagating the meme.

The tourists behave like lemmings or like the sheep of Panurge (Rabelais - France - 16th Century)

You may also say that they are "blind followers".

Herd mentality?

Herd mentality, or mob mentality, describes how people are influenced by their peers to adopt certain behaviors, follow trends, and/or purchase items. Examples of the herd mentality include stock market trends, superstition and home décor. Social psychologists study the related topics of group intelligence, crowd wisdom, and decentralized decision making. [Wikipedia]

Also - Clichéd Photo Poses