It is usually an add-on, and it has a length
Art on one or two accent nails adds ten minutes; art across all ten adds twenty-five. Those are not estimates — they are what the calendar reserves, which is why a gel manicure with art on all ten nails is offered to you as 1 hour 25 minutes rather than as 1 hour.
Bring a picture
Everybody apologises for this and nobody should. A photograph is a better brief than any description, and it lets us tell you before we start whether what you want fits in the time you have booked. If it does not, you will hear that at the beginning rather than at the point where seven nails are done and the shop is closing.
Chrome and cat-eye are finishes, not paintings
Chrome is a powder rubbed into a cured top coat until it goes mirrored. Cat-eye is magnetic particles pulled into a band while the colour is still wet, one nail at a time. Both are on the add-on list at ten minutes each, both only work over gel, and both show every ridge underneath — which is why the prep matters more for these than for anything else on the list.
The lookbook is painted on loose tips
Everything in the gallery on this site was painted on loose tips rather than on a hand, on quiet Sunday afternoons. That is so what you are choosing is the finish and not somebody's hands, and there is a page that explains it properly.