Virtue Signalling
Etymology
The phrase joins "virtue" with "signalling," the latter borrowed from evolutionary biology and economics, where a costly signal advertises a hidden quality. Its pejorative political use was popularized by the British writer James Bartholomew in a 2015 Spectator article, though he later noted he had not coined it and earlier uses exist. The signalling metaphor implies the display, not the virtue, is the real aim.
noun phrase · /VUR-choo SIG-nuh-ling/
Publicly expressing moral views mainly to advertise one’s own goodness rather than to actually help or change anything.
What it names
A real gap between performing a value and practicing it — though it is worth using carefully, since the label is easily thrown at any sincere stance one happens to dislike.
Example
Changing a profile picture for a day can be genuine solidarity or just virtue signalling — the difference is what you do next.
Related idea
Performative activism is the same critique aimed at action rather than speech — protest as spectacle — where the point is being seen to care.