Is it considered a valid return (rajʿah) if flirtatious and private pictures and words are exchanged, even if the husband did not verbally pronounce the return and officially affirmed in court that he would not take his wife back?

The definitive say in marital disputes belongs to the Sharia (definition) court because the judge listens to both parties, requests evidence, and his ruling is binding. Resumption of the marriage is not valid merely by exchanging pictures and words of love. A husband may take his wife back during her 'iddah (definition) (waiting period) without her permission, but after the 'iddah, it is not permissible except with her consent and a new contract. The dowry is a right of the wife, and the husband is not allowed to take any part of it without her consent. It is necessary to refer to the Sharia judiciary.