Identifying neutral and hot on wire connector
Looks like they just covered the connector and textured everything.
Using a volt meter put one side to the cover plate then one side of the receptacle should show line voltage the other much less or nothing,
there is a possibility of a voltage being measured on the neutral with no connection to a load (called phantom voltage) in that case the lower voltage is neutral.
It matters for safety if wired wrong a metallic fixture may be energized on conductive surfaces but since there is a ground this should trip the breaker.