Yandex is a Russian based reverse image search engine. Like Canadian based Tineye. It seems to be more reliable now in many cases than Tineye. It goes back to when Google announced that they were putting restrictions on pictures. Google may or may not go out to pictures that may be copyrighted. It depends. The results: Two years ago, a search on Tineye may have brought back twenty to fifty responses on an adult image. Currently though, with the Google restrictions, that same adult image search on Tineye is coming back now with zero results. (I don't have the Chrome extension installed for Tineye so results may be different.)
Just keep trying. You can't mark this thread solved. Too many pieces to the puzzle are missing.