And the fact is that humans can't reliably identify emotions from photographs, so there's zero chance for AI.
While I don't agree with much of what she writes, the psychologist Lisa Feldman Barrett gives an excellent overview of why at the start of her book "How Emotions are Made".
But a short explanation is that 1) emotions are expressed not just with the face but with the whole body, 2) the expression of emotion is a sequence of changes over time that can't be captured in a single frame, 3) there is extreme overlap in the expression of emotions (e.g. a seemingly grimaced look could either be painful anguish or ecstatic surprise) and 4) while we do have instinctual expressions for emotions (smile/frown/etc.), we learn culturally how and when to hide, show, fake, or otherwise modify these by habit, as well as consciously do so for our immediate purposes.
So we humans obviously do recognize emotions in others, but we do so with a huge variety of cues, we still frequently get it wrong, and we do a far better job when we share the same culture, and also know the individual person well. (Think how some people express anger with aggressive shouting, others by silently withdrawing.)
Most evidence for the idea that emotions can be identified (and cross-culturally) comes from the research of Paul Ekman, but this was limited to 6 "basic" emotions with photographs of highly exaggerated/stylized faces performed by actors. It has no relevance to whether real-life, non-"staged" emotions can be reliably detected.
So any AI products designed to supposedly recognize emotions are necessarily snake oil. I assume they are reliably measuring facial expressions, but facial expressions simply cannot be mapped to actual emotions in any kind of reliable way in the real world.