"I get asked this all the time," she captioned her now viral post, that has amassed more than five million views.
In the footage, Katie can be seen in her Macca's uniform showing viewers a drive-through camera during her shift.
"There is a camera and it takes a picture of you and your car," she said.
"So maybe don't pick your nose when you order … because we see it and we judge you," she joked.
In a statement to the Herald, a McDonald's New Zealand spokesperson said the drive-thru camera systems are different to that seen in Australia.
They said New Zealand staff do not have to operate four lanes.
"All restaurants in New Zealand will have some level of a camera in the Drive-Thru for security purposes, and signage notifies all customers that the cameras are in use.
"Restaurants with a dual lane or tandem Drive Thru – two lanes with two speaker boxes – have cameras which are high above cars to indicate who is next in line for our cashiers."
The McDonald's Australia employee's video soon went viral, and it didn't take long for people to comment on her video.
"I thought they just had crazy memory," one TikTok user confessed.
"I'm shook, oh my god," wrote another.
"I always wondered this with ones with two lanes (that merge into one, never understood the point of them," a third person said, while a fourth added, "They can see me all this time I've been going in my PJs and dressing gown, oh god."
Some joked that despite there being cameras, staff "still manage to get orders wrong".
"And y'all still gave my order to the car in front," one person wrote.
Another staffer chimed in to say the Macca's he works at "it's not that advanced".
"We just have to figure it out."
Adding to the horror that staff are watching, Macca's staff also commented that they "hear" everything from the moment a customer's car activates the sensor, which then triggers their headset to turn on.
"In fact we hear everything you say the minute you're at the speaker," a staffer said.
So, there you have it. Just be prepared to know they may be watching.. and listening, when you least expect it.
- Additional reporting by the Herald