Scaffold Resource uses products chosen specifically to meet the unique requirements of each job. When dealing with a structure as historic and noteworthy as the Mid-Hudson Bridge, Scaffold Resource made sure to protect the bridge itself as well as the travelers below.
GFCI (ground-fault circuit-interrupter) protection is required for many receptacles (outlets) throughout the house and outdoors. This protection can be provided either by a GFCI breaker or GFCI receptacles. There are advantages and disadvantages to each approach, depending on the installation.
That outlet is called a ground-fault circuit interrupter (GFCI). It's there to protect people from electrical shock, so it is completely different from a fuse. The question on appliance plugs talks about fuses.