The reaction is a response to an event which you have strong feelings for it.
Some cases are:-
a) Death or Mourning :- Shock,Pain and Sadness
b) A good day :- Energetic,Cheerful and full of Joy
c) A marriage or an occasion :- Excitement and Energetic mood
These are some common examples i have given. To see more mood reactions try to observe different people in different circumstances.