I received a 250MB epub file and unzipped it (with 7z) and just recompress it's jpeg's to ~50% size (not dimensions), keeping the same files names (with IfranView).
I reziped to .epub and loaded it to my android tabs. Two apps open it but will display each picture twice. Once without adjacent text and the second time with text I do not have any special epub authoring software.
Why it happened and can I correct it?