If the file is altered locally, then tray needs to show the sign

[SEFI2]

If the transferred file is altered locally or remotely there should be automatic detection to show that there are difference perhaps based on a checksum. This way we can offer the user the chance to retransfer and synchronize the already transferred yet changed files. For example the tool notices that the user transferred a file A from local to remote, then changed the file locally, then the tool might show a different maybe yellow icon in the Operation Status column, to indicate the file is now out of sync, and offer to start the transfer again maybe making the button active.