1) if jpg or png file size is less than 1 MB and 1 000 000 in bytes file upload succeeds.
2) if jpg or png file size is about 1 MB (for example, 0.99 MB or 1.039.133 in bytes) I get an error from screenshot.
3) if jpg or png file size is more than 1 MB (for example, 1.02 MB) I get the error "Image size must be less than 1MB" (as it should be).