ah, i've been giving GRIS a miss lately as it seems quite frankly shit !... i tried yandex, wondered if it might have been a case of image reversal, as i didn't try that
You need to use several in concert, each may find hits that others don't. Yandex does seem to find alot, perhaps its coverage of non-Western sources and a "different approach" to crawling Western content sites gets to assets not found by slightly more cautious Western search engines.

GRIS may "miss" because they may be actively trying to divert you to other results they can monetize, I am becoming more and more cynical about the honesty and rigour of their service.
I will probably have a dig around for more Image search engines with different or no commercial leanings. If you find any that show some competency then please do share
