Almost every flag in the extensive collection of world flags is recognizable as rectangular. But among all the nations, there are two exceptions—nations with perfect squares for their official flags.

Every national flag tells a story. Stitched into the colors, symbols, and patterns of these rectangular pieces of cloth are centuries of history, sacrifice, cultural identity, and national aspiration.

Created by Dentsu Canada, Assemble the World reimagines 18 national flags using, turning home furnishings into a playful expression of fandom You may have noticed there’s a World Cup going on. Even if ...