I think this particular illusion is very compelling precisely because it is just that: an illusion. Many optical illusions operate via deficiencies in the human visual system, and could thus be somewhat reproduced through visual means. However, this is not so for the impossible object, this illusion instead uses the human brain's propensity to interpret 2d figures as 3d object. Because it is impossible this object to exist in 3d space, the fact is that this 'object' exists only in our minds, and thus in a way cannot be reproduced. Thus I cannot find any examples of an impossible object in the 'wider world' apart from those specifically depicted in art.