Leveling a front load washer (as shown in the video) is important for both--preventing "wobble" as well as for appearance.
A new washer & dryer positioned next to each other at the same height looks very neat.
Although most retailer installers *do* level the machines--what REALLY needs to be done--is to add a single large towel into the washer tub and to put the washer in a SPIN ONLY cycle. This will "mimic" an imbalanced-spin condition.
After 3 to 5 minutes the tub will enter a High Speed Spin Mode.
Using a wrenchette (supplied with most new front loaders) a more precise leveling of the washer can be done.
If there's any rocking or thumping sound during ramp-up-to high-speed-spin----adjust the *left* or *right* leveling leg until the noise completely stops.
Lock the leveling leg nuts.
This will NOT solve vibration/noise on wood floors--unless the washer is a brand/model designed specifically for wood floor laundry rooms.
Entering a washer into a Spin Cycle by activating the SERVICE TEST MODE should *NEVER* be done.
In most front load washers--the software feature which monitors the tub for an imbalance condition is DEACTIVATED during the SERVICE MODE.
The result will be an unbelievable amount of vibration/shaking/hopping--far worst than would normally be the case.