GNOME Videos, formally known as "Totem", is a really limited video player made by the GNOME project. It is unclear if they designed it to be used on a phone or just wanted to remove as many useful features as possible; whatever went wrong it's not a very usable piece of software.
Features and usability
GNOME Videos, or just "Videos" as they call it, supposedly has a "searchable list of local videos". In reality it's got a searchable list of video files you previously opened in that player; searching for files you have lying around your attached disks yield no results.
To open a file you have to "Add a local video" to your video "library" (of already opened files). You can't add a folder tree or a single folder. You can add multiple files from the same folder.
Further, there is no playlist feature. Totem, which it is based on, had one.
If you are using KDE or XFCE4 and you'd like to easily make the window sticky then you can't; there is no window titlebar. There's not much else in terms of features either. Or preferences.
GNOME Videos does have a very prominent tab called "Channels". There is of course no way to add or remove channels; the reason is probably that it would be a feature and features can confuse people and confusing people go against GNOME guidelines. Anyway, the channels you get are "Rai.tv", "Apple Movie Trailers", "Euronews" and "The Guardian Videos".
A brief test of various files reveals that GNOME Videos has problems playing quite a few files, specially older MPEG2 and MPEG4 files. It can't even do video playback right.
All in all GNOME Videos feels more like a video player for a mobile phone designed by a 12 year old than it feels like a desktop application. It's just horrible.