A yellow highlight box will appear around the edges of the shape when the pointer of your hand is inside of the object. Then, to grab an object, press and hold down your index finger, we can now re-position the object. Releasing the index finger will place the object at the desired location.
You can grab objects out of the build menu using your laser pointer. Point at the desired object, press and hold the index finger, and it will appear at the pointer of your hand.