Gmail's New Buttons

Jono Xia, writing about the recent Gmail redesign:

But these icons are particularly bad. Again with the cult of minimalism: the icons are so streamlined and featureless that they all look the same: a row of meaningless, square, grey objects. When I want to mark something as spam, I used to be able to click the “spam” button. Now I have to mouse over each square grey object one at a time, looking for the one that pops up a “Report Spam” tooltip. (It’s the stop sign. Why a stop sign? I don’t know. Years of using GUIs have trained me to interpret a stop sign as an error message.)

Update

Henning Hoefer notes that Google added a setting to revert back to the text labels. I don't think this is the right way to improve a user interface.