These are not windjammers though, are they? They look like pretty vanilla, small sail boats (IDK sloops ketches, or yawls… (Wrong … Too many masts. They’re schooners.) Windjammer was a derogatory moniker for the sailing ships built after steel construction became common. Much much taller masts, wire rigging etc.
Correct me if I’m wrong, but I’d expect a much larger hull and 3 or 4 very tall masts, with something like four square sails per mast.
The Windjammers outcompeted steam vessels for many transoceanic trade routes because they don’t require the constant input of coal to operate.
https://en.m.wikipedia.org/wiki/Windjammer
Picture on that article depicts a ship with six square sails.
EDIT: looked at the picture again. I believe they are schooners.
Yes, the introduction of steel to sail boat construction allowed bullders to blow previous size constraints out of the water. They were considered big and ugly. IRC Windjammer was an insulting name because they didn’t look like elegant craft that rode the wind, but wind jammers.