Here is the usual terrible training video on HIPAA. It is pretty vague as well, but basically covers the generalities.
https://www.youtube.com/watch?v=mEu6NGPA0CgPhotography of a resident could be considered PHI if the photograph contains personally identifiable information, or information that could indicate condition or health status.
This is one of the big reasons why many conditions, such as having an indwelling catheter, or -ostomy, can be very difficult. If the DPoA or the Resident do not want to be seen without their catheter or -ostomy concealed, any such exposure is a HIPAA violation.
Some jerkwad on facebook can take a full face photograph/video of a resident with dementia (doing full on dementia related behaviors, such as swearing), post it on face book, and amend a name. BAM- HIPAA violation. really big one. These days, with photo recognition being baked into more and more things online, just the face alone could be disastrous.
Given that our friends at Facebook and pals just LOOOOOOOOOOOVE personally identifiable information, facebook is not friendly with nursing or medical facilities. Pretty much at all. Using social media inside a nursing facility is highly discouraged. It is very easy for a simple post that has names redacted, to lead to a breach of PHI, when reviewed against a circle of facebook friends, their postings, and the like. This is especially problematic, since facebook does everything it possibly can to datamine facebook postings, and to create inter-relation matricies between friends, post content, pictures, and names, including pretty sophisticated face recognition routines. As a hypothetical, say you (as a care giver) say you are going to be taking your residents to Golden Corral after taking them on a shopping trip, and what city, on facebook. You don't specify where or what golden corral, just that you are going. All by itself, this is pretty harmless. However, your facebook friends might say "Hey, I saw [facility transport vehicle] at such and such golden corral!" and our dipshit with the camera might have photographed bad resident behavior at the golden corral in question, and mention the facility, based on the transport vehicle's markings. He might not know the resident's names, but facebook might. Especially if the residents themselves have facebook accounts, such as to communicate with grandkids. Suddenly, there is enough information for facebook's facial recognition software to trawl, and connect some dots. It is able to positively identify the facility, the location, the residents (by name), their associations, and if the image contains any other PHI, such as previously mentioned dignity damaging devices, facebook now has unauthorized PHI, and they got it because (they are fucking greedy assholes that push the envelope, and) you posted some apparently innocuous information about a planned outing.
Many facilities have rules in place to prevent this, by explicitly stating that any discussion, regardless of how obfuscated, of PHI outside of direct work environments is strictly prohibited. Many others will outright terminate you if they catch you using social media at work.
When planning an outing, in today's world where big corporate is watching, it is very important to get written release for all residents that will be attending outings, and to get that release in writing from either the resident themselves (if legally competent to do so), or from the DPoA.
"reasonable measures" is a wiggle-word, but that is as far as I can tell, the standard. If you take every reasonable precaution to avoid the disclosure, and report when disclosures happen, so that your duty officers can make policy amendments to prevent future disclosures of that type, you are in the clear. Just be aware that modern digital media is actively antagonistic to privacy, and that means complete forbidding of those technologies may be necessary to assure reasonable protection status. Many facilities enforce such a rule, and for this very reason. It is unreasonable to rip a camera out of a duchebag's hands. It IS reasonable to ask them that they not take the picture, and to respect your residents and their privacy. When the douchebag fails to comply, report the unauthorized photography.
That is about all you can do really. Just be mindful about your communication, when, and where-- and do everything you possibly can to avoid revealing the information.