From phone via email

EDIT: It seem to be possible to upload images via email.

www.ipernity.com/pref/mailpost

IMPORTANT! Don't tell that unique email address of your's to others!

Each user supposedly gets an unique email address. Please click 'Learn more, settings...' on that page and read the instructions carefully. It was reported this does not work, but for me it did. Maybe there is some limit for the file size, either defined by your own email provider (sender) or by ipernity (recipient). So, make sure you don't try to email very large files. I recommend below 1 MB files (e.g. less than 2048 pixel wide jpeg on 80% quality).

UPDATE: Other tests shows that even bigger files (~3MB) goes through. Maybe the user's own email provider then may set some limits.

UPDATE: Christian Bucher also noticed the page is (and has always been) secured, using https, which keeps the unique email address you get as safe.