Does LibreOffice prohibit this ?
If anything is unclear for you in the project license, you are welcome to consult your lawyer; or mail to legal@documentfoundation.org for an official clarification. Advices of other users on a site like this are unlikely to serve as a good foundation for your decisions.
Note that the license has clause 2.1
, that covers “display”.
I recomend to ask at the already given address, as there is also in 2.3:
This License does not grant any rights in the trademarks, service marks, or logos of any Contributor
So there could be legal problems when you have for example a logo of TDF in your Screenshot. Take special care, when it comes to extensions…
I would not say prohibit, but the use of graphics/photos/artwork is complicated and different in several countries. Some rights can’t be “moved”, but you can get a “allowance to use free of charge”.