I'm interested in answering questions that relate to "how do I achieve this effect?", but I don't see a tag for that type of question. Is there one?
I think the closest we have is reverse-engineering. Tag summary is:
Analysis of an image to determine setup and techniques that could be used to achieve certain properties of the image.
- not obvious to non-geeks
- has a hardware implication (despite the tag description)
Just effect is pretty common in practice, even though that's kind of terrible.
A lot of the questions we get - unfortunately many of them too broad & are soon closed - tend to start with the assumption that everything is a 'filter' as in a Snapchat/Instagram filter.
This one is actually looking for equivalents to Snapchat filters - How can I recreate Snapchat's built-in filter effects?
Maybe we should have a whats-this-effect tag, perhaps linked back to reverse-engineering?
There's also post-processing (which feels odd to me, as I've always known it as post-production rather than processing.)
Personally, I like these types of challenge, if the question or examples are sufficiently well-honed to know precisely what 'effect' is being asked about.
Link to How should we handle the "what (Instagram) filter is makes this photo" type questions? for the current state of play on some of these questions.