Cells, expelling fat in the blood. Okay. First, let's wonder. What is fat in blood? An illness. Goodie. So would the body make a normal process of expelling fat into the blood? Most probably not. It's when things aren't working well that fat ends up into the blood stream.
Now, what is fat for in the body? Storage. It's stored, nothing else. What circulates in blood is always - when things work right - sugar. The extra energy is carried to fat cells as sugar, which take it in and afterwards turn it into fat. And if the energy is needed, they turn it back to sugar and release it.
Of course! And even if your laser, in some weird way, does force fat cells to release the fat, assuming you don't have a heart attack, your cells won't be able to use it. Muscles use sugar. Not fat. And if, in an even weirder way (because honestly it's hormones released upon physical activity or starvation, etc. that do that - how would a laser cause that?), the laser forces the cells to turn their fat into sugar and release it, assuming it doesn't carry you towards diabetes, what good would it be. What happens when there's a sugar rush in the blood and you're not moving? Not weight loss.
Maybe, perhaps, by stretching reality a ton, it would do something if you were running on a treadmill WHILE the technician lasers you.
And to begin with, even if we assume their scientific principles are right, think of it. Would a laser, not strong enough to pierce you, have any effect on your fat cells? Maybe superficial fat, which is a small portion of your fat. Might help with cellulitis. Maybe, perhaps. But actual weight loss? Yeah, no, I don't believe so. If you have any amount of fat significant enough to think about this treatment, it's probably too deep to actually be reached.
Unless it works in a completely different way and it's just the explanation that's rubbish, don't go.
A rip-off, just like grapefruit diets, protein bars and whatnot. Except on a whole new level because a "professional" with a machine pseudo-scientific explanations is going to do it on you with tons of promises, making you believe it blindly.
But really, if people just remembered their high school biology a tiny bit, they would just chuckle at such a thing. I'm not even saying that because of the usual reasons - "if a miracle existed, we'd all be thin" or "you can sell anything as a fat loss product if you include exercise before the After picture", etc. No, those people actually made the effort of "scientifically" explaining it, and it doesn't make sense in the slightest. That's unforgiveable.
They could pretend to move fat, to reduce the waist circumference, to smooth surface fat to reduce cellulitis. All those things would be a bit surprising but I can't readily say they're impossible. But burning fat, seriously, they're taking you for a fool.