The current icon for "Browse" is "/devices/input-mouse", and doesn't properly represent the action. A much better icon to use for the "Browse" action would be "/actions/transform-move", since it's represents the exact action (moving the page up/down/left/right). In the current (4.9) Oxygen icons, the icon is represented by four arrows, but is synonyms to the "hand" (move) icon from other icon packs. Reproducible: Always
"Browse" doesn't only represent moving the page up/down/left/right, in the "Browse" mode you can also click on links or right click in annotations, etc. that's why we used the mouse icon since the transform or hand icons are only a subset of the features you get in that mode.
Even so, I think the a "Hand" icon would still be better suited. As examples, Foxit Reader and PDF-XChange, to name just two, use exactly a hand icon for this exact behaviour that includes moving the page and clicking linking or interacting with PDF elements. Adobe Reader even calls it the "Hand tool", and you can select it on right click. Overall, using a Hand icon provides a much more clear representations what the "Browse" action does.
Do you kde-usability guys have an opinion in this?
It is difficult to have a strong opinion on this subject without A/B testing. However, having looked at other PDF and document readers, the hand icon looks like a de-facto standard, so I think it is a good idea to switch to it.
So use transform-move or use hand? Which is the hand icon btw?
Oups, I posted my comment at completely wrong position. Once again, with a tendency to answer your last question with use the "hand icon". You are talking about Okular menu extra > navigation, right? Actually, the content cursor is a hand pointer and changes to hand press (I don't know the correct name). So it doesn't match with the menu icon. IMHO, the primary task of "browse" (in my German menu "navigation") is moving the sheet around with the goodie of left and right click (with changing cursor in that case). Therefore I agree with mokush, at least since all mouse actions could assigned to the rather unspecific input icon. And a benefit of changing the icon to actions/transform-move would be a better distinction of all 5 icons. BTW: It's quite unusual to place 5 options in the menu but separate them in the toolbar. Perhaps it makes sense to adopt the toolbar structure to the menu. I say "perhaps" because the five options belong to different tasks and the intended use is not easy to understand. Wouldn't it be better to separate view and selection? PS: German translation is buggy: the function is called "Navigation" in menu and "Durchsuchen" in toolbar. That points to a complicated original name.
If the german translation is broken, open a new bug, don't hijack this one. And please center on the thing we are discussing. By broadening the discussion all you get is me close to do a "wontfix" or "invalid" on this bug.
Opened separate bug 312567 for translation Browse/Durchsuchen/Navigation.
Ok, we acknowledge there's some friction on the icon for the browse action, well try to find a way to find out which icon is better for it.
I make the review of breeze icons in all kde apps and also for breeze the /actions/transform-move icon is the right one and in according to the Icon HIG it also say only use actions icons for toolbars. https://techbase.kde.org/Projects/Usability/HIG/IconDesign