Hello.  I upgraded my Leap-15.5 installation to Leap 15.6 as a “guest”
operating system in Oracle Corporation’s VM (Virtual “Machine”) VirtualBox
7.0.18r162988 (Qt5.15.2).  After beginning the “booting” of that Leap-15.6
installation I reached a login screen, or dialog box.  On such a login screen
using computer software I have been used to seeing a white rectangle, or edit
control, into which to enter a password.

Unusual phenomenon 1:  But I did not such a white rectangle, or edit control
there.

Nevertheless I could enter my regular-user password and on that login screen
see corresponding black discs against an otherwise probably dark-blue-colored
background.  And each one of those black discs probably corresponded to a
character I entered for my regular-user password.  Then, after I entered all of
the characters of my regular-user password, I could press down on my computer
keyboard’s “Enter” key, and, if I entered my regular-user password correctly,
then see a large black rectangle leading toward my Leap-15.6 “desktop.” 
Probably a good and new feature was that when I had my computer keyboard’s
“Caps Lock” key activated I could see a notice above the area into which to
enter my regular-user password reading “Caps Lock is on”.

Unusual phenomenon 2:  A second unusual feature was that the word “Password” on
that screen was not in bright, white-colored letters, as the letters in my name
on that same screen were white colored, but were instead in perhaps light-blue-
or gray-colored letters against the otherwise dark-blue-colored background.

Also near the lower-left-hand corner of that login screen I could click and, if
I wished to do so, select a different type of “Desktop Session” from the one
already displayed there.  The initial lettering there was in white-colored
letters.

Unusual phenomenon 3a:  But after clicking once on the particular type of
“Desktop Session” displayed there, a column of choices appeared, all in
black-colored letters, against the otherwise dark-blue-colored background.

Unusual phenomenon 3b:  And at least one of those black-colored choices
appeared partly on top of the white-colored, already-set choice for “Desktop
Session”.  

These four unusual phenomena on the login screen have occurred when “booting”
into Leap 15.6 using either one of the following versions, of course one at a
time, of the software package kernel-default:

6.4.0-150600.23.7.3.x86_64 from Leap 15.6, and the Leap-15.5 version “passed
along” to Leap 15.6 of
5.14.21-150500.55.65.1.x86_64.

Question 1a:  Which ones, if any, of these four phenomena, were by design for
Leap 15.6?

Question 1b:  And which ones of these four phenomena would you consider as
unintentional and therefore due to one or more errors in my Leap-15.6
installation within VirtualBox 7.0.18r162988 (Qt5.15.2)?