NextCloud Client's tray icon would best represent the program if it used NextCloud's actual program logo.

The current green circle with a check is not intuitive at all to recognize it's purpose. I often look at it and think to myself "What the heck is this icon?" as it's, IMHO, not very useful in it's current state: if https://github.com/nextcloud/desktop/issues/1184 was implemented, the tray icon would be useful on a daily basis instead of rare and random basis.

Run NextCloud client on Windows.
Client version: 2.6.4stable-Win64 (build 20200303)
Operating system: Windows 10 2004
OS language: English
Qt version used by client package (Linux only, see also Settings dialog): n/a
Client package (From Nextcloud or distro) (Linux only): n/a
Installation path of client: C:\Program Files\Nextcloud
n/a
n/a
@jancborchardt opinion there?
You are welcome to read the whole background discussion about why specifically we are _not_ using the Nextcloud icon for the "all synced" state at https://github.com/nextcloud/desktop/pull/416 :)
The short answer is – to quote myself from that thread:
The logo as default state will be confusing as every other system uses a definite checkmark for this state. I'd really prefer we keep the Nextcloud icon for the "not set up yet"/"connecting" state since that is the one you will see initially, and because a logo is not proper feedback that everything is fine.
(I had a feeling that state/status was going to be the reasoning and I'm prepared with counterpoint.)
@jancborchardt There are a number of ways that the logo can be used and still show state.
My suggestions on state:
ALL IS GOOD - color logo
SYNCING - logo spinning (color cycling could look cool too)
OFFLINE/CONNECTING - gray version of logo
NOT SETUP: logo blinking or with superimposed exclamation mark
You could also use notifications for change of state. REF: https://docs.microsoft.com/en-us/windows/win32/uxguide/mess-notif
Whatever method is chosen to show state, industry standard is to display the program's icon.
Using the program icon = instant recognition as it matches the graphic imprinted on the user's brain via the website, the installation, the icon they click to run the program, the icon in the corner of the running program, etc. etc.
Case in point:

You can probably easily recognize most of these tray icons and what they represent. Even the programs that you don't recognize, you can most likely make an educated guess on what they are; i.e. the system resource monitors. Also note the red circle and line/no symbol overlayed on top of Keepass2 as it does not have a database open; e.g. intuitive icon that also shows state.
For sh!ts and giggles, I disabled my network interface to see and show the icons status change. You'll notice that Dropbox went to a gray logo and Outlook overlayed an exclamation mark. Both are excellent examples of keeping recognition of the program via the logo and showing state.

Simply put, using the program logo is intuitive.
IMHO: The current verdict is not a good one as it goes against the normal patterns of tray icon UI.
I hope you'll reconsider.
I see that in the same way.
Using the current icon leafes everyone back with an icon that gives no clu what program it is.
Imagine if everyone is doing the same as nextcloud. All icons in the tray will look the same! Awful
Most helpful comment
(I had a feeling that state/status was going to be the reasoning and I'm prepared with counterpoint.)
@jancborchardt There are a number of ways that the logo can be used and still show state.
My suggestions on state:
ALL IS GOOD - color logo
SYNCING - logo spinning (color cycling could look cool too)
OFFLINE/CONNECTING - gray version of logo
NOT SETUP: logo blinking or with superimposed exclamation mark
You could also use notifications for change of state. REF: https://docs.microsoft.com/en-us/windows/win32/uxguide/mess-notif
Whatever method is chosen to show state, industry standard is to display the program's icon.
Using the program icon = instant recognition as it matches the graphic imprinted on the user's brain via the website, the installation, the icon they click to run the program, the icon in the corner of the running program, etc. etc.
Case in point:
You can probably easily recognize most of these tray icons and what they represent. Even the programs that you don't recognize, you can most likely make an educated guess on what they are; i.e. the system resource monitors. Also note the red circle and line/no symbol overlayed on top of Keepass2 as it does not have a database open; e.g. intuitive icon that also shows state.
For sh!ts and giggles, I disabled my network interface to see and show the icons status change. You'll notice that Dropbox went to a gray logo and Outlook overlayed an exclamation mark. Both are excellent examples of keeping recognition of the program via the logo and showing state.
Simply put, using the program logo is intuitive.
IMHO: The current verdict is not a good one as it goes against the normal patterns of tray icon UI.
I hope you'll reconsider.