in borrowed plumes

The common European idiom 'to dress oneself in borrowed plumes' derives from the fable.

That evening, when we started for the schoolhouse, Sara Ray was among us, decked out in borrowed plumes.

In Borrowed Plumes (1926)

It is the Latin version too that lies behind the popular idiom 'to adorn oneself (or strut) in borrowed plumes', used against empty pretensions.

Go, throng each other's drawing-rooms, Ye idols of a petty clique: Strut your brief hour in borrowed plumes, And make your penny-trumpets squeak.

"And then you won't know me, sir; and I shall not be your Jane Eyre any longer, but an ape in a harlequin's jacket--a jay in borrowed plumes.

In some other time and place he might have taken pleasure in his new array, but he knew now too clearly that this was a deadly serious matter, and no masquerade in borrowed plumes.

The print suggests the relationship between the proverb, which focuses on reputation gained by presentation rather than merit, and the idiom 'dressed in borrowed plumes', which draws attention to another fraudulent aspect of reputation.

The rich relation's parlour was in festival array, and the country cousin sails in, looking back at her sweeping flounces with such artless rapture that no one had the heart to laugh at the pretty jay in borrowed plumes.