The first is not actually a Lemon Oil; it is instead Olive Oil infused with Lemon. See entry on Colonna Oils for one example of this.
The second is a very strong essence of Lemon, stronger than Lemon Extract, which is cold pressed from lemon rinds and mixed with a neutral oil. It is sold in very small bottles. Be very wary of using more than 1/4 teaspoon in any recipe. Lemon Oil has better flavour than Lemon Extract, but still doesn’t carry the real nuances that lemon zest would.
A well-known brand in North America is Furst-McNess.
Don’t confuse either type of Lemon Oil with the lemon oil that is a furniture polish.
1/8 teaspoon lemon oil for baking = 1 teaspoon lemon extract = 1 teaspoon zest