Nah, a distraction like that can be good for a young child, so long as it’s not the only technique you use over time. A young child crying over their parent not being present is just a sign of separation anxiety. It’s nothing like giving a misbehaving child a reward (mobile device) to make them stop misbehaving (which is what I think the parents in the study were often doing), though one still shouldn’t give a child a mobile device, as the study states it likely stunts a child’s ability to cope with certain emotions. I’ve known many adults who have undergone immense emotional stress over an event & they often find a distraction in a project or hobby. It may not be perfect, but it helps keep them from dwelling on the stressful event &/or doing something extreme.