When headphones or earphones are connected to the PHONES jack on the BOSS IR-2, it always uses the LINE setting, regardless of the type knob and [AMBIENCE] knob settings configured for the OUTPUT (A/MONO, B) jacks.
Disconnect the headphones or earphones from the PHONES jack to hear the sound matched to the amp type setting from the connected amp on the OUTPUT (A/MONO, B) jacks instead.