See IRC discussion:

<drago01> aday, hughsie: btw. is it intentional that gnome-software never shows progress bars? when installing a game that takes a while to download the spinner does not seem right
<drago01> it spins forever and you have no idea when it will finish or how far it is
<aday> drago01: i thought the install button showed a progress bar
<hughsie> aday, how would we show writing/verifying? or just make it 50% of the bar each?
<drago01> aday: no it doesn't
<aday> drago01: it's been a while since i've looked at it, tbh
<hughsie> drago01, there's no progress ui anywhere; although the data is available to us trivially
<drago01> aday, hughsie: ok
<hughsie> if it appears on a mockup somewhere either kalev or I can add it easily
<aday> i'm absolutely certain that we had a progress bar in the button at some point
<aday> at least, i remember discussing it
<drago01> should I file a bug?
<aday> https://raw.githubusercontent.com/gnome-design-team/gnome-mockups/master/software/version2/software-installed.png
<aday> pretty sure that i saw that in real life
<aday> but maybe i dreamt it :)
<drago01> aday: just double checked no it does not tryed to install openarena
<drago01> it just shows the spinner
<aday> yeah doesn't seem to do that now
<hughsie> aday, ohh, pretty -- is that a new widget or can a GtkButton do that already?
<aday> i do seem to recall talking about it, maybe with mclasen. he might remember