Can you make out what are those “flat plate like” things? The second picture would aid your answer.
Yes the skin of the “thavil” (the percussion instrument of this part of the country) being dried post rains. They need to be taut for getting the real bang while playing this instrument, hence even a little bit of rain / dampness would reduce the rhythm. So the need for it to be dry is high.
Seen at Arcot road, Near Vadapalani.