As shown in the figure, point O is the midpoint of line segment AD, with AO and DO as sides respectively, making equilateral triangle OAB and triangle OCD on the same side of line segment AD, connecting AC and BD to intersect with E, and connecting BC to find the size of angle AEB. (2) If O is not the midpoint of AD and other conditions remain unchanged, ask whether the size of AEB has changed and explain the reasons.