4 ideas
Each sketch opens with a one-line definition of the vice, such as flattery as a degrading association profitable to the flatterer. It then switches to 'the sort of man who...' and lists concrete things he says and does. The abstraction is briefly named, then made recognizable entirely through observable behavior, so a reader can spot the type in the street.
After sacrificing an ox, the man of petty ambition nails its skull, wreathed in ribbons, opposite his front door so every visitor knows he could afford an ox. He also keeps a pet jackdaw and buys it a little ladder and a tiny bronze shield to hop about with. Here ambition shrinks to staging tokens of status for spectators rather than achieving anything.
Walking beside his patron, the flatterer says people are all looking at him. He plucks lint from his cloak and picks straw out of his hair, and he laughs at his feeble jokes, stuffing his own cloak into his mouth as if he cannot contain himself. He also buys apples and pears for the patron's children, turning intimate service and exaggerated reaction into a transaction for advantage.
The late learner at sixty memorizes verses and fumbles them at drinking parties, and has his son drill him in the commands of military exercise. He takes up riding and falls off, and he wrestles and practices at the gymnasium alongside young men. The fault is not learning itself but acquiring youthful accomplishments at the wrong age in order to show them off, which makes the effort ridiculous and sometimes injurious.