Hello landlord, I am happy to answer your question!

You right-click on someone else's signature file picture, save the picture as, save it to your computer, then upload it to Baidu Space Album, open the picture, click the copy address above, and then go to the post bar, under the avatar. The penultimate one, my settings, signature file settings, add a set of signature files, right-click to paste, fill in the picture name, submit, wait for review, complete