Attach icon/image/gif to field

Hi I have faced with issue, that I want to add a gif of a loader to the left side of the caption to inform  user that this field is calculating and change it depending on its content For example if it is empty there should be loader gif if it is not it should be like a green tick.

Let's say I have already added MyIcon.png and I have field with this data:

{
				"operation": "insert",
				"name": "AgbRegisterFormMessage",
				"values": {
					"layout": {
						"colSpan": 23,
						"rowSpan": 1,
						"column": 1,
						"row": 1,
						"layoutName": "AgbIssuanceTabGridLayout"
					},
					"bindTo": "AgbRegisterFormMessage",
					"enabled": false
				},
				"parentName": "AgbIssuanceTabGridLayout",
				"propertyName": "items",
				"index": 3
			},