15.5 kde lock screen desgin - looks like glitch in the matrix or video mem errors?

Users, was briefly startled when 15.5 booted up after the upgrade on some 15.4 kde machine, first i had thought the reboot of the bare metal has had left some graphics memory in a deranged state or something. those lines, and blurred, from the background of new 15.5 kde, look odd to me, when being seen blurry or in the clear on the logon screen or when you enter your password there. later i figured that ought to be the new 15.5 kde desktop background picture design or something. those horizontal lines, always feel odd when they come into view, show desktop et al ty.