Viewnior is another image viewer that is included in most Linux distros. It is significantly better than Eye of Gnome (EOG) because it can handle very large images. As such I expect Viewnior will become the default image viewer on all of my Linux computers.
I got to hear about Viewnior because I recently built a VM using Manjaro Linux. This distro is derived from Arch Linux, and compared to my ultimately abandoned efforts to get an Arch VM built from the core distro files, due to the complexity of their installation task which lacks a built in installer, Manjaro has been very easy to set up (using the XFCE edition). As this edition of Manjaro includes Qgis 3.0.2 I will be using this VM to run Qgis 3 on mainpc.
Since Lubuntu 18.04 was released I have now installed two computers with it: the NUC in my bedroom, and a Toshiba R700 laptop that I have. On both of them, I installed LXQt and sddm on top of Lubuntu, since the Lubuntu community hasn't yet got a version of LXQt they are willing to release for production yet. When you install sddm on top of Lubuntu you get the KDE Plasma login screen thrown in.
I have thought about putting Lxqt onto some of my other computers but it is only up to release 0.12 and in fact has a long way to go in terms of being usable and the development seems to be very slow. For now I am just leaving it with some VMs and Lubuntu computers mentioned above. However to make serverpc look nicer I have installed sddm with the Plasma Breeze theme and put some new icon themes into XFCE to make it look cooler.