That's it, yes.
If I may quote from the story on a well-known website:
QUOTE
In a larger story about the development of the Toronado I came across this photo of the same car. It seems Oldsmobile – and David North specifically – wanted the Toronado to be a smaller car, about the size of a Camaro, but GM insisted it use the larger E-body (Riviera, Eldorado) shell. Bill Mitchell even sided with North and Oldsmobile to maintain the smaller dimensions and had a shortened Toronado mocked up, to no avail. This car, however, appears to be a later attempt to pitch the same idea; GM Design staff cut a foot from the wheelbase of a 1969 model and shortened the overhang to create an AMX-like Toro.
UNQUOTE
Here's another picture of the puzzle car: