| One line (centered) | Two lines (not centered) | 
|  |  | 
Probably the Text widget itself is getting centered, but we're not configuring the Text itself to center its content, which I think we'd do with a TextAlign.center.
It looks like it's been this way since the text was introduced, in a97ac42. Assigning @PIG208, the author of that commit. 🙂