http://swonderstzr43aczpcwdoyc25vwxngyromja7pyb5sf26ap3v535sxqd.onion/resources/about-photos-how-can-i-check-and-make-sure-they-do-not-contain-any-metadata-exif-for-malicious-people-to-track-me-or-identify-me
This could be the XMP, MPF (which may also contain additional EXIF), IPTC, Photoshop, Adobe, XAP, XAP-Ext, proprietary content and so on. Some cameras / devices embed serial numbers or unique references which could be used for tracking purposes. Sometimes copyrights are added to the photo which may include your name which is acceptable if that was your intention.