Disassociating doesn't always work like played out in films or TV, sadly. It's terrifying, and often find it hard to trust what's in front of you. Familiarity is needed, as it acts to ground you, and a key part of this is to feel safe on a number of different levels. Simply having photos alone may not be enough, unless those photos are something you regularly examine and experience.
Grounding is a common method of dealing with anxiety and other mental health issues. The idea of finding your place, finding familiarity, centring yourself. Something you are very used to doing normally and when safe is important, as is having that also associated very strongly with being safe.
For some people, photos will work well for this - they might capture moments with strong association with safety and happiness. Some people may be able to instead use an object, a talisman of sorts.
For others, or for when the disassociation is worse, a single grounding method may not be enough. It's about building the complete story - getting home and watching something familiar. The grounding only happens from weight of evidence.
Finally, there's something you don't hear talked about much. Coming back around from disassociating can be utterly terrifying in it's own right. Both as one tries to return, and after coming back. Having multiple entirely different means to ground helps with this.