As of today's patch, the PC UI received a major style overhaul, having most (if not all) elements completely made into flat colors. This was extremely negatively received in the
PTS Feedback Thread, with only a few players actually liking it and no developer responses for the reason behind the change.
Here's an example of existing company logos "modernized" to understand what I mean:

And here's some screenshots of the UI changes that players have shared in the Feedback Thread:
EDIT:
@Dack_Janiels has made an add-on that brings back the old UI style, you can download it from below:
https://www.esoui.com/downloads/info4130-Pre101046UI.html
EDIT 2: Here's some comparisons of a few UI .dds image files that I've extracted from U45 (left) and U46 (right):
Boss bar bracket:

Death recap background:

Fill all dye slots:

Tel Var meter:

Revive meter:

Loading screen edges:

Trading window (player ready to trade):

There isn't ANY file size or resolution difference at all!
Edited by Maitsukas on June 16, 2025 12:03PM PC-EU
@maitsukas
Posting the Infinite Archive and Imperial City Weekly Vendor updates.
Also trying out new Main Quests, Companions, ToT decks, Events and Styles on PTS.
Thoughts on the PC UI art style "modernization"? 518 votes
I have mixed feelings about it