For those of you who notice the padlock next to a name means that the Bulb is turned on, the bulb can drag back and forth while a program is running in the presentation mode or on the Web site of the Scratch.
Observe that the lock will open next to the name means Light Bulb can use draggable while the program is running in presentation mode. Or on the website of Scratch
Observe the lock is next to the name Bulb will open means, the bulbs can use the mouse to drag back and forth as the programs in presentation mode, or on the site. Scratch.