The answer is yes to both really, at least in the period that I am familiar with. It was a show in that much of it was consciously put on and more so the more something was subject to scrutiny. But it was real in that it was actually done, and it was reflective of something substantial in their culture. My answer will be on Late Medieval and Early Modern Europe, more on the Early Modern side and more in England than anywhere else. I think the culture of the Early Modern period is one of the chief examples that you might have in mind, and it's certainly an example where what you say really does occur, perhaps even more so than any other time and place. The culture of the Early Modern is a culture of performance, and the higher the circle of society the more that social games of display were necessary and dramatic.

Let's start with a fun source I'm familiar with; the Progresses and Processions series by John Nichols, from which I will reference Elizabeth Volume 3, 4 and 5, and James volume 1 and 2, in the period from 1590-1614 which I'm most familiar with. Throughout these volumes pageantry and rhetoric clearly play a major role in important events. The progress itself is a giant pageant and its display to onlookers and to the various significant hosts was one of its purposes. Not only was the procession of people a constant display, they are frequently received and entertained with various theatrical conceits including actors, poetry, music and visual set-pieces. You can also see in this collection official letters, and the ones from the monarch are often quite high in style.

One particular example here worth looking at is a performance at Gray's Inn, a legal university essentially, given for the Queen in 1594. This was part of a tradition of Christmas Princes at the Inns of Court, a slightly strange conceit where obeisance would be paid to a young man elected as a temporary monarch. The Prince of Purpoole for Gray's Inn in 1594 was Henry Holmes and given the titles: "Prince of Purpoole, Arch Duke of Stapulia and Bernardia, Duke of High and Nether Holborn, Marquis of St Giles and Tottenham Count Palatine of Bloomsbury and Clerkenwell Great Lord of the Cantons of Islington Kentish Town Paddington, and Knight's Bridge, Knight of the Most Heroical Order of the Helmet, and Sovereign of the same". One level, this is a rather odd tradition to perform before a monarch given it essentially mocks the styles of the English crown, complete with the "Most Heroical Order of the Helmet" as an obvious reference to the Most Honourable Order of the Garter. On the other hand, this can be seen as an affectionate parody, and its farcicalness as safely self-mocking; many of the locations are local sites like St Giles and Islington.

Manorial houses were also displays themselves, and with the degree of social contact and networking at this time they were far from private. The apex of this is the "prodigy house" one built primarily for court progresses. One examples is the Theobalds in Hertfordshire. “Theobalds, Hertfordshire: The Plan and Interiors of an Elizabethan Country House” by Emil Cole (2017) analysed this historical construction in detail. It includes numerous rooms to host the court, with various halls, parlours and dining rooms where people could gather with various degree of intimacy. In this way, it was based of the structure and social layers of palaces. As you might expect for what became the Cecil family's main country house, it included heraldric elements including a window with coats of arms painted on it in the winter parlour. This was not just a house, it was a site of governance and a monument to Lord Burghley's ambitions; it was meant to be seen. Elizabeth visited it on progress at least eleven times, the most of any single house for a courtier, and she was entertained (and sometimes politically pressured) with performances and pageantry by her hosts.

This also extended to fashion, which was considered a major class indicator and even regulated by laws (though patchily enforced). Colours were also associated with symbolism, as seen in “Rainbow for a Reign: The Colours of a Queen’s Wardrobe” by Jane A. Lawson (2007) Costumes covered with symbolism could sometimes be seen at major events; in the 17th century Queen Anna wore a dress with silk worms and mulberry leaves to promote an attempt at a native silk industry and had her portrait done in this dress.

Poetry could certainly include elaborate speech. One thing that stands out about reading pre-Modern pre-Industrial Revolution English (and to some extent 19th century English too) is how there are many long sentences punctuated only with numerous commas. Full-stops seem to be less used. And the phrasing can be fairly torturous to us, describing anal sex might come out as something like "put your seed otherwise than you should have" and the use of double adjectives, "good and kind" for example , is pretty common. Colourful metaphors and pepperings of other languages are pretty common amongst the Early Modern high class. Letters were frequently shared with servants, apprentices, family members to some extent, sometimes copies being circulated to different households of relatives even if the letter is addressed to one household in particular. Therefore, many of them were written with the understanding they might be seen by others and were not particularly private. This goes for middle and poorer families, who with smaller houses actually had less room for privacy even as there are less servants around. Indeed, even when truly private correspondence occurs such as that of James VI of Scotland with English courtiers prior to his accession the language is still colourful and formal but the importance of the letters produces the same result despite being covert (see “Correspondence of King James VI. of Scotland with Sir Robert Cecil and Others in England, During the Reign of Queen Elizabeth: With an Appendix Containing Papers Illustrative of Transactions Between King James and Robert Earl of Essex” edited by John Bruce of the Camden Society).