The EXT:copyright is overwriting fluid partials of the TYPO3 API.
Like in the illustration below the partials of the EXT:copyright will be included at
If you don't have any effect in the frontend – if a copyright is not displayed – the cause is probably, that partials of another extension overwrite image properties.
You can check this effect, if you include the EXT:copyright with the highest element id like
lib.contentElement.partialRootPaths.21 > lib.contentElement.partialRootPaths.9999 = EXT:copyright/Resources/Private/Partials/