The script explains -
Pulling away from the portrait, Victoria moves through the room, amazed by the hand-crafted furniture and jewelry.- before it gets to today's quote:
Page 55 - Barnabas (CONT'D): 'The first Barnabas Collins was devoted to her. They were engaged to be married.'
And in addition to that, Barnabas also says "There was a time when this house was filled with light... and laughter." And that was most probably added because, as we'll recall (see reply #595), Barnabas was actually scripted to say that in the dropped scene on the way to Josette's room.