The southern tomb of the Pyramid Complex of Djoser is a prototype of the Old Kingdom Satellite Pyramids. The reliefs on the panels in Djoser's southern tomb represent the king wearing the white Crown and running holding the flail. These scenes in the southern tomb can be interpreted as representations of the sed festival. 16
Therefore I propose a new theory on the function of the Satellite Pyramid: that it was used
as a changing room for the ritual of the sed festivaI.
The first part of the quote is on the right track as to the purpose of the satellite pyramids.
But the last part is a poor interpretation of what is shown in the three reliefs.
The southern reliefs show the King's 'run' in the Sed Festival with glyphs for the two halves of the sky and the three markers for the end of the run.
The southern tomb thus represents a place in the southern sky that marks the end of the 'run' across the sky.
The most likely place is the Belt stars as we see these in the centre of Senenmut's ceiling depicting the two halves of the sky.
The satellite pyramid was normally placed south of the main pyramid and was enclosed within the perimeter wall.
The perimeter wall and its contents represented the whole cosmos in the Sed Festival with its northern and southern halves of the sky.
Regarding G1-d in particular, this is less clear as it was outside the perimeter wall and was not on the south side.