Custom GROQ Request in the Preview / Prepare Functions

export default {
    name: 'singleImage',
    title: 'Single image',
    type: 'object',
    fields: [
        {name: 'image', type: 'image'}
    ],
    preview: {
        select: {
            image: 'image'
        },
        prepare: ({image}) => {
            console.log(image)
            // todo: get image original filename
            return {
                title: 'Single image',
                media: image
            }
        }
    }
}

select: {
   'filename': 'image.asset.originalFilename'
}

export default {
    title: 'Image',
    name: 'imageAlt',
    type: 'image',
    preview: {
        select: {
            title: 'asset.originalFilename',
            media: 'asset'
        }
    }
}