The command-line section of the Emacs info pages says that WIDTH and
HEIGHT are supposed to apply to *all* frames. Current behavior is that
it only applies to the first, third, fifth, etc. but not second,
fourth, etc. frames:
`-g WIDTHxHEIGHT[{+-}XOFFSET{+-}YOFFSET]]'
`--geometry=WIDTHxHEIGHT[{+-}XOFFSET{+-}YOFFSET]]'
Specify the size WIDTH and HEIGHT (measured in character columns
and lines), and positions XOFFSET and YOFFSET (measured in
pixels). The WIDTH and HEIGHT parameters apply to all frames,
whereas XOFFSET and YOFFSET only to the initial frame.