From the picture you've shared, it appears that your friend’s prayer plant is experiencing a common issue known as "edema." Edema occurs when the plant absorbs water faster than it can be used or transpired, leading to water pressure that causes blisters or bumps on the leaves. These bumps may look like white or pale spots and can be mistaken for pests such as scale.

This condition is often seen in plants that have been watered too abundantly or when there's high humidity combined with moist soil conditions. It's not harmful in the long term but adjusting watering practices can help prevent further occurrences. Ensure the plant's soil is well-draining and allow it to dry out slightly between waterings. Also, improving air circulation around the plant can help.

It would be helpful to closely monitor the plant for any changes. If the bumps start to spread significantly or you notice actual insects (which would indicate a pest problem rather than edema), further investigation and potentially different treatment might be necessary.

Thank you!! So much, I’ll pass it on and monitor. Grateful :)

Looks like spider mites to me.