Should patients with mild covid be in "prone" position than lying on their back?

Depends: Prone positioning is recommended by some physicians who treat Covid patients with respiratory tract involvement. They recommend this for both patients on ventilators and ones not on ventilators. A specialist makes the call. The thinking in nonventilator patients is that proning may prevent their need to be placed on a ventilator as proning is felt to improve expansion of parts of the lungs.

COVID 19 concerns: If symptoms are mild, there is probably not significant respiratory compromise. Thus, being placed in a prone position is not likely to be necessary.

Not necessary: No reason to remain in prone position during a mild Covid infection, unless the patient feels more comfortable that way. Supine position would seem to be preferable if any respiratory discomfort is present.