If I use a standard editor and paste an image from the clipboard (say in Windows), it creates a legit entry like:

When synced, I can see it on my iPad just fine.
Now I switch to the rich editor. If I don't do anything, this image stays as is. However, if I resize it by dragging the corner, it generates this code:
<img src="file://C:/Users/My%20Name/.config/joplin-desktop/resources/44a441caa2a54954878a3233ac355679.png?t=1607463897224" alt="00c184081521595338b54ca3bc80769b.png" width="636" height="517">
This is obviously wrong because it explicitly references my user folder, and, indeed, after syncing, I cannot see it anywhere else.
Now, when I paste from clipboard directly into rich-text and do not do any resizing, I get this:

which is also wrong.
So, the conclusion is that the current rich-text editor does not handle images well.
Joplin 1.4.19 (prod, win32)
Client ID: 5fba6475197f40cca19ec4fe8027582c
Sync Version: 2
Profile Version: 34
Keychain Supported: Yes
Revision: de123ee58 (master)