Non-porous describes a surface that does not readily absorb liquid into open pores. The description usually applies to the exposed material, not every layer behind it.
What this means at your property
Glass may be non-porous while the frame, sealant joints or wall surrounding it can retain moisture. Similarly, a smooth floor finish can conceal a wet substrate. Surface appearance alone does not describe the entire assembly.
Does a non-porous finish always mean cleaning is enough?
No. Evaluate the residue, surface condition, joints and underlying materials. Ask whether the assessment covers hidden moisture and whether the proposed cleaning product is compatible with the finish.