It appears that both the one and the other were designed for use rather than for ostentation.

From The History of the Decline and Fall of the Roman Empire by Edward Gibbon, Chapter VII

As long as that emperor lived, Africa was happy under the administration of his worthy representative; after the barbarous Maximin had usurped the throne, Gordianus alleviated the miseries which he was unable to prevent. When he reluctantly accepted the purple, he was above fourscore years old; a last and valuable remains of the happy age of the Antonines, whose virtues he revived in his own conduct, and celebrated in an elegant poem of thirty books. With the venerable proconsul, his son, who had accompanied him into Africa as his lieutenant, was likewise declared emperor. His manners were less pure, but his character was equally amiable with that of his father. Twenty-two acknowledged concubines, and a library of sixty-two thousand volumes, attested the variety of his inclinations; and from the productions which he left behind him, it appears that both the one and the other were designed for use rather than for ostentation. The Roman people acknowledged in the features of the younger Gordian the resemblance of Scipio Africanus, recollected with pleasure that his mother was the grand-daughter of Antoninus Pius, and rested the public hope on those latent virtues which had hitherto, as they fondly imagined, lain concealed in the luxurious indolence of a private life.