Bearing in mind the observational proof for the oblate envelope of 
Cas we
also examined elliptical gaussian models for interpreting our observed visibilities
in natural light. The position angle of the major axis of this elliptical envelope was
taken as 
to the East from the North according to Mark III observations
(Quirrenbach et al. 1993). Our best fit leads to a major axis of 
mas and a flattening of 
. Note that the gaussian model extent
taken at 1 
corresponds analytically to a smaller value than the uniform disk
model diameter. The present major axes and flattening estimates are comparable to the
results of the Mark III in H
, namely 3.2 mas and .72 for the major axis and the
flatenning of 
Cas envelope. On the other hand, from a previous interferometric run on
the GI2T Stee et al. reported that the continuum emission of the envelope must essentially
originate within 3-4 stellar radii (Stee et al. 1995), a result also inferred from
IR studies (Waters & Marlborough 1992). We find the continuum envelope twice as large as those
estimates. The discrepancy might be explained by the fact that Stee et al. did not include the
scattering of the photospheric light by the envelope for computing their continuum intensity map.
This would mean that the free-free and free-bound emissions originate close to the central star
whilst the scattering is chiefly produced in the outer regions of the envelope. In principle
interfero-polarimetric observations should have confirmed this conclusion if higher accuracies
than our upper limit of 1.3 to 
/
were obtained. One can
reasonably speculate that improved interfero-polarimetry in the future should ultimately
constrain the density and temperature distributions throughout the envelope among line-driven
or rotationnally enhanced winds (Cassinelli & Hoffman 1975; Poeckert & Marlborough 1978).