Tarn's optics widen and brighten behind his mask. Honestly, he was not expecting such a large impact blast from the tiny weapon. and the girl's giggle at the destruction was downright charming. Perhaps humans aren't so useless after all...

Walking over to investigate the damage he lets out a low chuckle himself.

"Very impressive. I dare say even equal to that of a Cybertronian scientist." And with such limited resources! It seems that she is able to make quite a bit out of scrap; which in this universe is and extremely important quality to have.