They mean linking as in [1] against a GPLv3 work to create a derived work. Simply including a GPLv3 application in a aggregation of different works (e.g. an OS image) does not require everything else to be GPLv3.
The GPLv3 only applies to a work and works derived from it, so either if you take an existing GPLv3 project and modify it or if you link against a GPLv3 project. In these cases, the other code needs to be under licenses that are compatible with the GPLv3.
This is clearly described in the GPLv3:
A compilation of a covered work with other separate and independent works, which are not by their nature extensions of the covered work, and which are not combined with it such as to form a larger program, in or on a volume of a storage or distribution medium, is called an "aggregate" if the compilation and its resulting copyright are not used to limit the access or legal rights of the compilation's users beyond what the individual works permit. Inclusion of a covered work in an aggregate does not cause this License to apply to the other parts of the aggregate.