Useful to knowYour questions,
considered.
Should an alcove be lit from the top or the sides?
Choose according to the surface and objects you want to show. A top wash, side grazing light and individual shelf lighting give different results, so compare a sample in the intended position.
Can I use these ideas in a bathroom alcove?
The design idea can transfer, but the specification may not. Have a qualified installer assess the bathroom location, moisture and full system. For shower niches, use the dedicated application guide.
How do I stop seeing a bright line inside the niche?
Design a recess or shielding edge around the normal sightlines, then test the actual depth and finish. A diffuser changes the appearance of the source but does not remove the need to consider glare.
What measurements should I send?
Provide the opening width, height and depth, any shelf positions and thicknesses, the proposed recess and cable entry. Add photos of the finish and the objects you want to display.