The images have to be uploaded to the LCDSysInfo device in order to use any of the special elements in GOverlay.
Images format are as follows:

<LCDSysInfo destination number>.<LCDSysInfo destinations used>.<imagename>.<extensionJPG>

Example 1:

040.1_dot.jpg

Meaning this image should be uploaded to the destination 40 and will use 1 destination slot (40)


Example 2:

115.4.gpubox.jpg

Meaning this image should be uploaded to the destination 115 and will use 4 destination slots (115,116,117,118)