Izzy has seen extraterrestrial sapients before but she's never met any. While LEC was a major front in the Incursion, it's not like they went door to door or anything. This is her first face-to-face encounter. Though that doesn't excuse her rudeness, it's a lot to take in. And she's had to take in a lot lately.
Very few humans have been close to any extraterrestrial sapients, though the amount could almost be called statistically insignificant. Earth is used to the idea that aliens are out there but next to nobody is used to the idea of actually meeting them even though the possibility of it happening is higher than it's ever been.
Prior to 1985, there has never been any alien presence on the entire planet. The concept got around but the truth of the matter is no one was particularly interested in visiting. As mentioned before, it's very far away and quite a bit off the beaten path. Of course, a lot of people would like to believe otherwise. But that's just not the case.
Now that Izzy finds herself in a rare position, perhaps she'll make the most of this. Or at the very least, be a bit less rude next time.