It is common in vexillological practice to shift symbols off-centre towards the hoist to aid visibility when the flag is flown, especially on sea, since the flag will move around less closer to the hoist. Examples are the flags of Palau or Bangladesh, where the discs are also set off-centre. This variant of the French flag for use as civil and naval ensign shows another kind of distortion towards the hoist for the same effect. The current Bundesdienstflagge (Federal Service Flag) of Germany also shows the German coat of arms slightly off-centre towards the hoist.

The old Reichskriegsflagge (Empire War Flag) of the Empire also shows a cross set off-centre, which here also evokes an association with the black-on-white Nordic cross of the Teutonic Knights Order. The newer Reichskriegsflagge from 1933-35 also shows an iron cross set off-centre towards the hoist, while the version from 1935 on - with slight variations again from 1938-1945 - shows a swastika on a black nordic cross shifted towards the hoist.

This might be another reason why the Swastika flag, when in use as a national flag and ensign, from 1935 on showed an off-centre Swastika and white disc. In the beginning, the flag of the NSDAP, the Hakenkreuzflagge (Swastika flag) with a centered disc was used together with the old black-white-red flag of the Empire as national flag, from 1935 on, only the Swastika flag, now with the off-centre disc, was used as national flag and ensign (there were differences in that on the naval/civil ensign, the Swastika was printed through, so it appeared mirrored on the reverse side; while the national flag had the Swastika stitched on on both sides so that it appeared the same on the front and the reverse). The Party flag continued to use the centered disc.

There's an article on precisely this topic in the #13 issue of the Flaggenkurier, the journal of the German Vexillological Society, which is out of print, but I'll see if I can get a hold on it.

On a related note, /r/vexillology is an excellent sub for questions regarding flag design and symbolism.

Edit: Here are some other examples of Nazi flags with the symbol offset towards the hoist: Reichsarbeitsdienst (Reich Work Service), top general RAD, middle RAD for women, below flag for sport/leisure boating. Didn't find the magazine issue I was looking for, but in another book (Hormann/Plaschke: Deutsche Flaggen: Geschichte, Tradition, Verwendung. Hamburg, Edition maritim 2006) I found a quotation from the Reich Flag Law, which specifically stated in its later incarnations that the disc and the Swastika were to be set off center towards the hoist, a specification which was missing from the 1935 law, which simply specified the Hakenkreuzflagge as national flag and ensign.

Edit 2: Thanks to whoever thought my little piece worthy of gold!