Artix Linux Forum

As a user you may not but as root you should be able to.
If sudo works try sudo pcmanfm
If not try $ su, login with root pw,
then pcmanfm

But if you change things around on that device and you don't know what it is you are doing you may never get it functional again.
By default the first user on the system gets the ID# 1000, the second 1001 and so on.  If you see 1001 then you only have one username and 1001 is unassigned.  If the second user was Roxy then you would see Roxy as the owner instead of 1001.
I don't know what ssdm is but the number of the user on that phone may match a system account on your main system.
Or is it sddm? 

You mean other drives of other linux systems?
I think sddm is user 999 unless this number is already taken by other "users".  So on some other system where 999 maybe LXDM while you are browsing through on your file manager it may appear as the owner is sddm just because on your artix system user 999 is assigned to the label sddm.

Not just sddm in particular, any DM, has a peculiar responsibility to be authorized/privileged to provide real login users with an appropriate configuration of X to enter into a specific desktop environment.  It is like a middleman between root and the user.

If you think this is weird wait till you see what systemd does, it manufactures users on the fly who login and out of your system, write logs, and you have no control of what and when they do stuff.  You seat around idleing with nothing running (that you know of) and users go in and out of the task-list. 

If you login console as root, who starts sddm?  Who is authorized to log you in as a user?  Should root be able to read the user's emai?

Those are advanced system-design questions that I am clueless about and prefer to stay this way

I don't know much about this stuff, what is right or wrong Linux philosophy. All I know is that I am always able to access my main current home folder (Manjaro OpenRC) from any other Linux I install on one of my drives. All that is required is either user or root password. I am not sure which one since I use same password for my user account and root.
But here, in Artix I cannot access my Manjaro OpenRC home folder. It's owned by whatever, 1001 or sddm.

For your phone make sure that these entries are in groups uucp:x:14: user name  adbusers:x:996:user name  storage:x:95:user name
android:x:1001:user name

I was talking about folder ownership of my other drives, not the phone. I just thought that not being able to mount phone storage has something to do with ownership.
ssdm was typo, it's sddm. Why would sddm be owner of any folder on my other drives?  I've never seen that before.
Thanks for being kind and trying to help.

For your phone make sure that these entries are in groups uucp:x:14: user name   adbusers:x:996:user name  storage:x:95:user name
android:x:1001:user name