TueriImgPlaceholder.js

class Img extends React.Component {

    constructor(props) {
        ...
        this.state = {
            ...
            fullsizeLoaded: false
        }

        ...

    }

    ...

    render() {

        // Destructure props and state
        ...
        const { isInViewport, width, fullsizeLoaded } = this.state

        ...
        
        // Modify the queryString for the LQIP image: replace the width param with a value 1/10 the fullsize
        const lqipQueryString = queryString.replace(`w=${ width }`, `w=${ Math.round(width * 0.1) }`)

        // Set the default styles. The full size image should be absolutely positioned within the <figure /> element
        const styles = {
            figure: {
                position: 'relative',
                margin: 0
            },
            lqip: {
                width: '100%',
                filter: 'blur(5px)',
                opacity: 1,
                transition: 'all 0.5s ease-in'
            },
            fullsize: {
                position: 'absolute',
                top: '0px',
                left: '0px',
                transition: 'all 0.5s ease-in'
            }
        }

        // When the fullsize image is loaded, fade out the LQIP
        if (fullsizeLoaded) {
            styles.lqip.opacity = 0
        }

        return(
            <figure
                style={ styles.figure }
                ...
            >
                {
                    isInViewport && width > 0 ? (
                        <React.Fragment>

                            {/* Load fullsize image in background */}
                            <img 
                                onLoad={ () => { this.setState({ fullsizeLoaded: true }) } }
                                style={ styles.fullsize }
                                src={`https://cdn.tueri.io/${ src }/${ kebabCase(alt) }.${ ext }${ queryString }`}
                                alt={ alt }
                            />

                            {/* Load LQIP in foreground */}
                            <img 
                                onLoad={ () => { this.setState({ lqipLoaded: true }) } }
                                style={ styles.lqip }
                                src={`https://cdn.tueri.io/${ src }/${ kebabCase(alt) }.${ ext }${ lqipQueryString }`} 
                                alt={ alt } 
                            />
                        </React.Fragment>
                    ) : null
                }            
            </figure>
        )

    }
}

...