This is absolutely a capacitor and not a resistor. It's probably not ever a good idea to short-circuit a missing component unless it's a fuse. Even then, it's not a very good idea.

Capacitors come in all different shapes and sizes. Have you seen the tantalum caps that we've used to replace the leaking cylinder-shaped electrolytic caps on these old Macs? They're yellow/orange and rectangular in shape and don't have specific polarity. Some look like round discs, some are green, yellow, black, blue, etc. Some are HUGE, some are extremely small.

Inductors also come in lots of different forms.