Is this ceiling pendant double insulated?
No. Class 2 (double insulated) devices are not fitted with a ground wire, and must not be grounded. Instead, they're constructed with much sturdier insulation to ensure that exposed parts cannot become live, even in the event of a fault occuring.

They're also required to display the double insulated symbol; a square within a square.

The cover over the terminal strip is to protect against fingers or metallic objects falling into the terminals.