Is Slavoj Zizek that famous?
He most surely is, Zizek has had appearances on authors @ google, a public 'debate with Julian Assange, has been the focus of 2 (soon to be 3) feature length documentaries, and is a fairly constant feature in news media in its many forms. Monikers such as 'the academic rock star' or 'the most dangerous philosopher in the West' illustrate just how difficult it is for both popular and alternative media to ignore Zizek.
Isn't imaginary the world before language?
this is not the case. At the website for Lacanian ink, a publication which Zizek has contributed a great deal to, it gives the following as an introduction:
The basis of the imaginary order is the formation of the ego in the
"mirror stage". Since the ego is formed by identifying with the
counterpart or specular image, "identification" is an important aspect
of the imaginary. The relationship whereby the ego is constituted by
identification is a locus of "alienation", which is another feature of
the imaginary, and is fundamentally narcissistic. The imaginary, a
realm of surface appearances which are deceptive, is structured by the
symbolic order. It also involves a linguistic dimension: whereas the
signifier is the foundation of the symbolic, the "signified" and
"signification" belong to the imaginary. Thus language has both
symbolic and imaginary aspects. Based on the specular image, the
imaginary is rooted in the subject's relationship to the body (the
image of the body).
So how can imginary be
colonized? And how can this "Tibet" world fantasy be in imginary?
I think a simple answer would be that through Zizek's inheritance of the notion of the imaginary from Lacan, it is in a way possible to say that the entirity of unconscious content in some way has 'colonial' origins (as opposed to 'native' or purely intrinsic). The primacy of what is other in Lacan over innate knowledge and ways of knowing is key to understanding the 3 registers of real, symbolic and imaginary.
Ideology does not conceal or distort an underlying reality (human
nature, social interests etc.) but rather reality itself cannot be
reproduced without ideological mystification (Zizek, 1989: 28). What
ideology offers is the symbolic construction of reality - the ultimate
fantasy - as a way to escape the traumatic effects of the Real.
So from this perspective a person's grasp of what Tibet 'is' endures inside a space in subjectivity which is structured by these phantasmatic reproductions.