Yeah, probably.

Looks like just a simple typo at first sight.
DepictsPanel.js has: if ( changes.length > 0 || removals().length > 0 ) {
Should probably be: if ( changes.length > 0 || removals.length > 0 ) {

I suspect that'll fix it.
(No time to commit, check & test right now, but I'll do so tomorrow unless someone else has in the meantime)

Which software project is this about? Something SDC'ish? Tags welcome. :)

Yup, I was just doing that :)

In T218318#5024932, @Aklapper wrote:

Which software project is this about? Something SDC'ish? Tags welcome. :)

Change 496561 had a related patch set uploaded (by Ha78na; owner: Ha78na):
[mediawiki/extensions/WikibaseMediaInfo@master] Can't save after deleting a statement

https://gerrit.wikimedia.org/r/496561

Change 496561 merged by jenkins-bot:
[mediawiki/extensions/WikibaseMediaInfo@master] Let statements be still saved after deleting a statement

https://gerrit.wikimedia.org/r/496561

Test Result

Status: ✅ PASS
OS: macOS Mojave
Browser: Chrome

Test Artifact(s):

Go to a File page where the file has one or more depicts statements.
Click 'edit' to edit the depicts statements.
Note that the 'publish' button is greyed out

Click the trash can to delete a statement
'publish' button not greyed out - you can save
Acceptance criteria:

When editing existing depicts and (only) removing one, user should be able to submit the form, saving the removal

@Ramsey-WMF tested and passed on Test Commons as well