Not sure why but my Ubuntu 18.10 has installed with a rather visually ugly login screen.
I’ve seen people with older versions have nicer login pages, am I missing anything? Here is a screenshot:
That looks to me like a standard
gdm3 greeter screen. Not showing a picture for your account is supposed to be safer (ie. revealing less about the account you are logging into).
You could always replace gdm with another greeter, (older Ubuntu used
gdm3 does provide some configuration
such as changing the logo icon, display background, and GTK theme
for which the following wiki may help https://wiki.debian.org/GDM otherwise a search engine scan provided me many howto's. (I didn't see a Ubuntu wiki page for gdm)