Depending on the geopolitical situation, these could also be ads from the future.
It's not German, it's Dutch.
One of the reviews in TFA mentions that they considered it too bulky to qualify as a "notebook" computer. This computer was on the heavy side of normal for a "laptop" of the day, but definitely not light for the day.
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A more fair comparison might be the Compaq LTE (1989), which had a hard-drive and weighed under 7 lbs (if someone can find a more specific number let me know). The LTE/386 came out not long after this, weighed 7.5lbs and had a similar thickness.
If you want to compare apples to apples, look at the Tecra 500CS from 1996 that was my first laptop in '97 - it cost me $700 practically new. (Then as now, ex-fleet machines are a great way to go, as long as you pick ones that were issued to people who hate computers.) For what this was doing half a decade later, it doesn't make the 1991 model look too shabby, although I concede nothing in those days had as much as one one-millionth of the price/performance of almost anything you can pick off a shelf today.
https://www.minuszerodegrees.net/manuals/Toshiba/Tecra/Toshi...