IMO no but an overhead light is usually a good idea and probably just pot lights in the ceiling

It just that the light fixture wiring is already in place.

The fixture wiring is probably controlled by a wall switch. You can use the wiring for the LED mirror. The mirror will become your vanity light. All will be wonderful!

^^^ you'll need wiring for the LED mirror - is that already in place in addition to the light fixture wiring?

To my read, it is not in place.

Yes, you can absolutely have a vanity light above a frameless LED mirror, but whether you should depends on what job the mirror lighting is actually doing.

Some LED mirrors are mainly decorative or ambient, while others are strong enough for real face lighting. If the mirror output is modest, an overhead fixture can still help fill shadows and make the guest bath feel more finished. If the mirror is already bright and evenly diffused, adding a vanity light may create visual clutter and more glare than benefit.

I work with a lighting and metal hardware manufacturer, so I look at this from a production and QC perspective. I would check lumen output, CRI, color temperature, driver quality, and whether the light is front-facing, backlit, or both. A lot of disappointment with LED mirrors comes from weak forward light, not from the mirror shape itself.

If it were my project, I would decide based on lighting performance first and style second.

Thank for such through input!