(a) Hence the 'The expression is more usually used less literally to mean disguising one's negative emotions.' (b) Are you saying that 'a situation where the front side has been held up for a show/event to function but the back stage that is holding it is a complete chaos/mess and is on the brink of falling apart' doesn't involve human agency (in the broader, beyond-thematic-role-in-sentence ... More @Wikipedia
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