I have yet to see a good angle in a picture either. What pictures do reveal is it is not a rack such as the 190A or Dora has, but as stated above is a more streamlined mount referred to as the "Ta152 tank carriage."
Actually, I'm looking through Dietmar Hermann's 152 book,
http://www.schifferbooks.com/newschiffer/book_template.php?isbn=0764308602, as I'm typing and am noticing a lot of things I missed before. A drawing of a Ta152B on p.32 seems to show the tank mounting. Looks like there isn't a hardpoint but 4 small supports holding the tank in place. Looking through some pictures where the underside of the fuselage is visible on parked Ta152s also reveals 4 small supports where a tank might attach on other Ta152s. See p.40, 47, and possibly 49. There is also a drawing of a Jumo 213E powered Ta152 with long-span wings (I'm guessing an H model) on p.63 showing the drop tank mount from the side.
As I mentioned in another post, p.73 describes the new tank mounting for the Ta152, and p.91 and 92 have pictures of a 152H with a drop tank attached. However, the mount is obscured by the undercarriage doors, but is clearly not a standard 190 rack and is very low profile.
