You would need to obtain permission from the owner of the photograph/s - presumably whoever uploaded it/them. (I have done this, and had no trouble getting the permission to reuse.)
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edited to add -- the image as attached to the John Theobald profile is not John.
This is an immage of William Lane and NOT John Theobald. See William Lane for the larger picture and the people who are in the picture.
Dear Martyn West,
Thank you for contacting the FamilySearch Support Team. Please we do not give support to WikiTree, but you can download the pictures from your FamilyTree and upload them to your WikiTree.
This is your original case description: Copying picture to wikitree
Regards,
FamilySearch
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