It's the way you say it
Irony has a lot to do with tone of voice. Your words are the opposite of what you mean, but your tone should match the situation. That means that your tone of voice should match the situation and not your words.
Listen to the audio and notice the tone of the speaker's voice. Notice also that her words do not match the situation.
Is it ironic?
Open the Exercise below and decide whether the tone of voice is ironic or not.