Images shot while the camera in the HEIF format cannot be played back on a smartphone.
HEIF format images can be defined as both 4:2:0 (8-bit) and 4:2:2 (10-bit). However, this camera only uses the 10-bit HEIF format in order to provide higher-quality images. While the 10-bit HEIF format complies with the standards defined by the ISO, 10-bit images may not be able to be displayed on smartphones or other devices that only support the 8-bit HEIF format.
To play back 10-bit HEIF images on a smartphone, try converting them to JPEG or TIFF files on a computer using the Imaging Edge Desktop software (provided separately) before transferring them to the smartphone.