Two pictures set side by side. The whole device lies in εἶτα, "and then." First a list of four participles with no comment at all: EXERCISEἐσθίοντες, καθεύδοντες, ὀχεύοντες, ἀποπατοῦντες — eating, sleeping, coupling, relieving themselves, "and the rest." Then the same grammatical form, the same run of participles, but now: DOGMAἀνδρονομούμενοι, γαυρούμενοι, χαλεπαίνοντες, ἐπιπλήττοντες — playing the lord, swaggering, growing angry, rebuking "from their height." Marcus passes no judgement: he simply butts the two frames together, and the second breaks against the first.
A word that is barely in the dictionaries. ἀνδρονομούμενοι is rare; it occurs nowhere else in the formatted part of the corpus. Roughly, "playing the ruling male." Rogovin renders it well — «корчат из себя важных господ». Long gives "imperious," losing the note of performance, of playing a part.
Time as a third frame. To the juxtaposition in space a temporal one is added, symmetrical in both directions: πρὸ ὀλίγου — "a little while ago" they were slaves (ἐδούλευον) to any number of people, and for what price (δι’ οἷα); μετ’ ὀλίγον — "in a little while" they will be in the same case. The arrogance is placed between two servitudes, and so appears not even as a vice but as a misunderstanding — a temporary blackout on a short stretch.
What it is for. The device is that of 10.13 ("what they are like in bed and at table") and 9.34 ("strip their poor souls bare"), and the purpose is the same — not contempt but the devaluing of their verdict: if this is what the judge is like, there is nothing to prize in his praise and nothing to suffer in his rebuke. Cf. 6.13 — the same device applied to things rather than to people. The governing discipline is assent, the sustaining one action.