My Mother is a Ghost on the Keystone Line

Between Coatesville and Paoli alerts come through my iPad and phone. They are from my mother’s account. They’re pictures I’m tagged in. They’re updates.
The pictures are of my mother’s face. Always just dark enough that I need to infer who it is. They are dark like a night shot without flash. Like it could be anyone’s thin jaw—anyone’s dark eyebrows, if I wanted it to be. I’m the only one tagged in the picture, and when the train reaches Ardmore they are removed. I want to ask my sister if she gets alerts, too, but maybe it would lead to worse questions.
By the second week I try to answer back. I write comments. I ask who is this? I look up how to deactivate a deceased person’s account on Facebook, but the process is too long and confusing to complete on the commute to work. Part of me doesn’t want it to stop.
The third week I get private messages that are blank as the train passes Exton. They appear constantly—one after another for a few minutes. I look at the pictures I’m tagged in, the empty notifications. I walk to the bathroom, gripping the headrests of other passengers’ seats along the way.
Leaning against the tiny metal sink, I hold up my phone. I take four shaky pictures of my face. I post them into messenger; I put them on my mother’s wall.
The next week, I get a single message just before Paoli. I turn off my phone before it disappears.