I imagine that Tim(as Robin) used to text Bruce all the time, photos, random thought, and memes. When Bruce "dies" Tim still texts him, more so random texts that are the tired thoughts and his goals. Sometimes it's out of habit, sometimes it's not. When Bruce cane back. He had lots of texts.
oh fuck NOW IM THINKING ABOUT THIS LIKE. Bruce takes the time to read every. single. text. and there are voicemails too, but he can only bring himself to listen to one or two, because he can’t bear to hear Tim’s sad, breaking voice or the way he chokes on his tears or how he sounds so tired. the next day he is Extra Nice to Tim to the point where Tim is like “youre creeping me out what is going on” but Bruce can’t bring himself to SAY anything since he’s bad at Emotions so he just. tries to tell Tim that he loves him and that he’s THERE for him through his actions.