Fix

commands/analyze/dominant-color.js

@@ -37,7 +37,7 @@ module.exports = class DominantColorCommand extends Command {
 		ctx.fillRect(0, 0, canvas.width, canvas.height);
 		const name = ntc.name(hexColor);
 		return msg.say(`${hexColor.toUpperCase()} - ${name[1]}`, {
-			files: [{ attachment: canvas.toBuffer(), name: 'dominant-color.png' }]
+			files: [{ attachment: canvas.toBuffer('image/png'), name: 'dominant-color.png' }]
 		});
 	}
 };

commands/analyze/faces.js

@@ -40,6 +40,6 @@ module.exports = class FacesCommand extends Command {
 			ctx.fillRect(face.box.xMin, face.box.yMax, face.box.width + lineSize, lineSize);
 			ctx.fillRect(face.box.xMax, face.box.yMin, lineSize, face.box.height);
 		}
-		return msg.say({ files: [{ attachment: canvas.toBuffer(), name: 'faces.png' }] });
+		return msg.say({ files: [{ attachment: canvas.toBuffer('image/png'), name: 'faces.png' }] });
 	}
 };