How can I edit/remove my pictures in Android -devices on desktop?
You can do this via WiFi, using a remote management app like e.g. AirDroid or, when on Windows, MyPhoneExplorer. There are a lot more apps like this, and they give you the added benefit of being able to manage a lot of other things remotely -- as e.g. reading/writing SMS, managing apps/contacts/ringtones, copying files between your device and your computer, and sometimes even backup stuff.

Most of them (like the mentioned AirDroid1) start a web service on your device, which you then can access with your browser. This often looks like a "virtual PC" (see screenshot below). Others (like here MyPhoneExplorer2) have a native PC-Client, which can even do more (like here: synchronizing with Outlook and others).



AirDroid managing pictures



MyPhoneExplorer Windows Client