Ploting model.plot_predict_is() method

[ghost]

When using the model.plot_predict_is() method, on the given plot we have a Blue line (what we are trying to predict) and the black line (the predictions)

Now if the blue line is Xt is the black line also Xt or is the black line Xt+1 meaning that upon visual inspection it should lead the blue line.

Thanks for your help, sometimes i come off as very unclear so don't hesitate to tell me if it's this time as well :)