Showing some heat stress. (upturned leaves on growing tips)
I'd ditch the rest of the foil, as it is useless in a growroom, closet or box. (collects, traps and radiates heat) Shiny...yes. Useful...no. Flat-white paint works great though.

Might want to raise the lights a tad also. Got a circulating fan on 'em? (can use it to blow-away the heat from the lights)