The globe is the message header the sender chose as properties in his mail preferences, or it is the default value for mail recieved from a user without Notes.
If you wish to "remove" it, be aware that you will be changing the design of your mail template without changing anything in the messages you are recieving.
Indeed, the image you see is not transmitted in the mail, only its identifier is. When you open the mail, your client takes the reference and displays the proper image from its internal file.
So, if it is mail size you are worried about, you have nothing to fear.
Pascal.