First from the parts of machine, the Vertical one cost is expensive. Then, portable one is for limited treatment. Like removal the tattoo, portable one you need adjust distance according the tattoo size.
But Vertical Nd Yag Laser is can adjust the treatment head for treatment. You just need to rotate the laser head to treat. And the big machine is full energy and high quality controlled solid-state laser comply with international standard. You can see the laser head is also different. The Portable Q-Switched Nd Yag Laser Device one needs to change the treatment head for treatment, to use different wavelength. It has three kinds of treatment head.
Then, The Vertical Nd Yag Laser one no need to change, Just adjust the laser head according to light spot.