Sentence:  An example, which I explore in detail in this book in Chap. 5, is the way that parents to be use their knowledge and expertise of how to mobilise digital memories (their affordances to use a mobile phone, to use social media platforms for example) to take sonographic image of the unborn foetius that they are given in a hospital out into the world and beyond. They thereby shift the <WSD>modality</WSD> of the medical procedure that generated the image-memory as part of an obstetric sonogram. 
Meaning of the word marked with <WSD> tags:  The way in which infrastructure and knowledge of how to use it give rise to a meaningful pattern of interaction (A concept in (Anthony Giddens)' structuration theory).