What pointed in European countries to the estate representative monarchy?

The monarchy was indicated by the fact that there was one person (monarch) at the head of the state, who passed on his power by inheritance.
The fact that this monarchy was estate was indicated by the fact that there were several groups of people in society, each of which had its own rights and responsibilities. (Nobles, clergy, third estate).
The representative point is that there was a body in the countries where representatives of different estates decided issues important for the state. (Parliament in England, Cortes in Spain, States General in France).