Digestion over the gut can be tricky. Especially if you are dealing with digestive issues like celiacs disease, inflammatory bowel disease, SIBO or even just low on digestive enzymes.
Another problem the absorption of vitamins over the gut is that there are detoxification enzymes in both the gut lining and the liver. By the time nutrients and vitamins make it into the tissues they are at dramatically lower dosages.
A liposomal vitamin absorbs directly into the bloodstream through the lymphatic system. This increases absorption dramatically.
To do this the vitamin is linked to a fat molecule. Small fat molecules are naturally absorbed into the bloodstream through the lymphatic system. So essentially the vitamin is a stowaway within the fat molecule.
Many vitamins and drugs are now being delivered into the body via the liposomal method. Vitamins that have traditionally been difficult to absorb like B12 or glutathione are know available as liposomals.
I like to think of this as the backdoor into the body. It's pretty ingenious and I expect to see more liposomal vitamins in the future.