Hi @jcrosstown ,
It means that there is a charging problem or a problem with the battery charge being too low.
Try removing the battery and then reinserting it and check if that resolves the problem. Here’s the ifixit [guide|122838] guide that may help with this.
Use a strong light and a magnifying glass to check that the phone’s charge port is clear and not obstructed with anything that may be preventing a good electrical connection or that stops the charger cable being inserted correctly. If there is any debris in the charge port enclosure, use a vacuum cleaner to try and suck it out. ''Do not'' use a metal pin or probe as this may damage the pins or cause electrical problems in the phone.
If the charge port seems to be clear and OK, check that the charger/charger cable works OK by either using it to charge another compatible device or trying a different known working compatible charge/charger cable and see if that works OK and that the phone begins to charge.
If still no good then try replacing the battery. Replacement batteries are available online. Just search for ''Moto E5 Play GK40 battery'' to find suppliers that suit you.