It is not Upwork's intention that you remove or "hide" your profile photo from your profile page.
You may, however, set your privacy setting to the maximum level, such that your profile page will not show up in any searches or on any browse lists.
Thanks for the quick answer !
But the system refuse to complete my profile set-up without adding my personal pic .My question is what if I don't want to add it at all for personal reasons , what are the steps I should follow without "hiding" all the profile ?
Upwork requires that freelancers us a clear, real photo of themselves on their profile pages.
If you don't want to do that, then that is fine. There are many freelance work platforms which do not have this requirement.