Distance is not the only variable#
People a few streets apart can lose internet access, while a cross-city network route may be available. The whole delivery path matters more than the number of kilometers on a map.
Consider connection quality#
Phone connectivity, Bluetooth and the receiving environment all affect the route. Treat a picture as a small everyday expression that the other person can notice when available.
Choose appropriate messages#
A small everyday thought fits the current design better than communication that must be acknowledged immediately. Use your existing, reliable ways to contact each other for urgent matters or time-critical arrangements.