Walk into a Lego store today and it’s not just pirate ships and Star Wars sets. There’s a bonsai tree, a bouquet of flowers, a vintage typewriter, even an artfully designed globe. Some are labeled “18+,” but the signal is clear without it. These sets are meant for adults. Over the last few years, Lego has quietly rebranded itself as more than a toy. It now offers entire product lines that cater to aesthetics and display, rather than imagination and play. The colors are softer, the pieces more...