Not quite sure what was going on, but this moth was fluttering its wings rapidly and incessantly, and moved slowly around on the ground. I watched it for more than 5 minutes. Poor photos because it did not stop fluttering!
I suggest this is the female of the species and the fluttering you observed may be a behavioural adaptation by the female to attrract a male by flappingits wings to dissipate airborne scent pheromones as a means of a attracting a male.