We are using Jira Service Management on the Cloud for an external helpdesk.
Very recently, when a customer replies to a JSM ticket via email, the system is adding a Green Arrow Icon to the reply comment.

Except when you view it on the screen it is big and fuzzy.

This is happening with multiple customers. It is not when the system sends out an email from the agent, it is only on the reply from the customers.
So I do not know where to look to make it stop happening. Does it have some internal meaning for Jira?
I've looked at all the automated notifications, but I don't think that really has any bearing here.