[anay]

 
(the single arrow shows resonance, I couldn't put a double arrow however I tried)
Hi,
I want to know if the compound on the right is a major contributor in the above resonance. I thought it is not, as carbon atom has an incomplete octet, but the answer given is yes, it is a major contributor. Some of my friends said it is because of Aromaticity in the ring, but I tried searching online and couldn't find anything saying that aromaticity in a resonance structure makes it a major contributor. So, I am asking here. How does Aromaticity help in significance of resonance structures? Any refrences/links with an explanation would be appreciated.
Thanks.

[sjb]

See e.g. http://www.quirkyscience.com/cyclopropenone-aromatic/  or https://en.wikipedia.org/w/index.php?title=Aromaticity&oldid=817768478 for definitions and discussions around aromaticity