Call function with setState from other component

I have the following setup:

import {getNewImage} from '...'

export default class FirstClass extends Component {
    constructor() {
        super();
        this.state = {
            imageURL: 'www.test.com/new.jpg',
        }
    }

    update = () => {
         this.setState({
             imageURL: 'www.test.com/updated.jpg',
         })
    }

    render() {
        return (
            <View>
                <Image
                    source={{ uri: this.state.imageURL }}
                />
            </View>
        );
    }
}

import Class1 from '...'

export default class SecondClass extends Component {
    render() {
        return (
            <TouchableOpacity onPress={() => new FirstClass().update()}>
                <Class1></Class1>
            </TouchableOpacity>
        );
    }
}

The problem is: it doesn't update the imageURL. I tried multiple things. Logging this inside of update gave back the right object. But trying to log the this.setState() gives an undefinded back.