Each element on your form can have a widget icon. The widget icon is a small icon that can be placed on the left side of the Label of the element. The image file name needs to match the data column name within the form.
In the Edit Form Properties window your link should be similar to the one in the image: dropbox://iformpics
Since each new form could have a Data Column Named “first_name”, you can re-use the same image across many forms but not in the same form. These images need to be placed in the same directory as your Image Label assets. So Lets say we have a Dropbox Folder called iformpics with the following images inside the iformpics folder: first_name.png and last_name.png
From here the Data Column Name's for the specified elements in FormBuilder should be called first_name and last_name. These data column names will then reference the PNG files in the dropbox folder.
**Images must be PNG (For best results, make images around 45 pixels x 45 Pixels)