Is there any way to make icons in Plasma 5 look the same as in KDE 4 (means better).
Just compare:

KDE 4 - Icons have no background and can be big, program names can be in 2, 3 rows.


Plasma 5 - it takes a lot of space but because of frame (no transparent background) icons are relatively small


Is this a permanent feature of Plasma 5 desktop icons or just a matter of configuration and style? I don't want to look at the frames.

Panel icons also look bad, because they are small in relation to panel width. I reported a bug report about that but nothing has been done so far.
https://bugs.kde.org/show_bug.cgi?id=349411

its the theme you're using , this thread should explain https://www.reddit.com/r/kde/comments/4 ... pacity_of/

To me it seems that you used a "Folderview" layout for your desktop in KDE4, i.e. the content of the "Desktop" folder was directly displayed.
Your "icons" in Plasma5 seem to be "Icon" plasmoids, whose "look" depends on the plasma theme.

You can still switch to the "Folderview" layout exactly like you did in KDE4. There hasn't really been a change in this regard.
Your "icons" should then be displayed without border.

The existing "Icon" plasmoids will not change though.
Better remove them and drag the applications again to the desktop.

OTOH, you can resize those "Icon" plasmoids to the preferred size like any other plasmoid.

Indeed "Folderview" cause the difference. But still there is frame size issue.
Compare frame in KDE 4 - Folderview


and Plasma 5, also Folderview


The frame around icons in Plasma 5 is much wider and this causes icons to be smaller in comparison to KDE 4. I show frame just to illustrate the issue but even when frame is not visible icons in Plasma 5 remain smaller. And because of wide frame they are in bigger distance from each other (look at how far is trash from home in terms of pixels). In KDE 4 icons are bigger, frame is narrower and icons seems to be closer to each other, which makes better impression.
Is the frame hardcoded or can be changed in configuration files?

apache wrote:Is the frame hardcoded or can be changed in configuration files?

AFAIK that frame was always hardcoded and still is.

Ok, thank you. I reported a bug
https://bugs.kde.org/show_bug.cgi?id=359077
I hope design team will do something about it.