Hi!
In this reaction, the chemical energy of of the products ( C2H4 & H2 ) are greater than the chemical energy of the reactant ( C2H6 ).
We can see this by the value of the change of enthalpy in the system which in this given reaction is +137 kJ.
The positive enthalpy change indicates that the energy invested in the reaction is more than the energy released, which means that the system has absorbed energy. This is often translated as the products being at a higher level of energy as compared to the products.
This is an example of an endothermic reaction, and you can develop a better understanding by referring to the attached picture.
Hope this helps!