If one wants to upload photos to Facebook so you switched the camera on, waiting until the WiFi signal is sent to the card and then connect the phone with the card that shows up as a router. After you start the app on your smartphone (Android and iOS) and the photos on the card are displayed. This is relatively fixed. It has now been found a photo that you want to upload, so this is transferred to the smartphone. Important here: ensures that the camera at least also in the JPEG mode receives, either JPEG or RAW + JPEG. RAW files are much too big and transferred to an imposition. The transfer of a 16 megapixel JPEG file takes about 10 seconds.
Thereafter, the photo may be filed by smartphone into the net.
Applications such as tethering etc. can forget because of the slow transmission speed.