Winona Ryder thought Snapchat was a snack.

Millie Bobby Brown, 12, said of Winona: "She thought Snapchat was chips!"

Winona explained her thinking and said: "Because in 'Heathers' we had the Snappy Snack Shack. It was the 7-Eleven place. I thought it was like food."

But Millie has been giving Winona lessons in Snapchat, though the 'Edward Scissorhands' star still isn't comfortable with it.

Millie said: "We were doing Snapchat on lunch. I have the best picture of her, with the bee [filter]. I got you at the right time. She got so scared."

Winona added to Variety: "It's like the mirrors when you go to the fair and they have those weird reflections, you're tiny or super stretched."

And it isn't just Snapchat that has left Winona baffled.

Millie explained how 'Stranger Things' fans have been dubbed 'The Strangers', comparing them with how Taylor Swift's supporters are known as 'Swifties'.

Her bemused co-star replied: "The Swifties? Like a Swifty Picker Upper? I have one of those to clean my house."

The brunette beauty is "overwhelmed" by the response to 'Stranger Things' and was "suspicious" of the positive reaction at first.

Winona said: "It's been overwhelming but in a really great way. I was actually sort of suspicious at first. I'd never experienced anything like it. It's been a long time since I've been in something that was getting so much attention. And back then it was a different kind of attention. We'd stay up all night and wait for the three papers, and have someone read them first, like, 'Is it OK?' "