Is it possible to have a computation graph that results from the application of the same model to two different inputs?

Yes this is not problem.

Do you have any idea on how the computation graph will be?

The Parameters from your net have been used twice and their gradient will correspond to these two use (the sum of the gradients).
If you’re not afraid of very verbose representation, you can use torchviz 3 to see how the graph will look like.