Extended the Greek precedent

1. Does the green sentence imply "the reek used mosaic to cover floors, but Romans extended its use to the decoration of walls"?

2. Doe the orange sentence mean "However, the subjects of Roman mosaics and paintings were still influenced by Greek subjects"?

Context:

Roman art owes much to Greek art, and many Greek sculptures are actually Roman copies. Roman use of mosaic extended the Greek precedent – a useful floor surface – to intricate wall decoration. Rome’s was a wealthy empire, and public and domestic decor reached a high point. Mosaics and painting were artistic media ideal for the less
ambitious architectural plans of people’s homes. The subjective influences remained Greek, however.