(don't take this seriously, it's the typical BF photo comment)

Dork disk = the plastic thing between the cassette (sprockets/cogs) and the rear spokes.
Reflectors = the... reflectors on the wheels, that grab inbetween the spokes.
Saddle-to-bar drop = your bars are way lower than your seat, usually related to a "racing" position, this puts more weight into your hands and requires some back flexibility.

These things aren't usually seen together, that's because i commented on it. Are you getting fitted to your new bike?

Don't take this as an offense, go ride that thing until it breaks, but make sure you are comfortable doing it