Answer
Direct Message stays in place if you are already in a two-person chat with them. A removed or unavailable contact may not be reachable. Tap an available photo for fullscreen, or use Forward or Download. Native iOS and Android also offer Share; browsers do not. Each action closes the card first.
Cards appear as a centered popup on desktop web and a bottom sheet on smaller screens. Swipe downward to dismiss the sheet; scroll its content to the top first if necessary. A full photo may load after a spinner; a missing or failed image keeps the neutral avatar. Photo actions are absent when no photo exists.