Correct, it has to be done one at a time. Which I think is good, IDs and annotations should should be important enough that you should take some time to do them.
It certainly varies by taxa and annotation field (sex and life stage of a snake may be difficult to determine without closely examining photographs), but butterflies and beetles can, in most cases, be confidently assigned to life stage (egg, larva, pupa, adult) by a quick glance.
@tiwane Tony - this is an example of inefficiency. I agree that it’s important, but it doesn’t take much time to deduce the life stage or flowering status of something. The need to open hundreds of observations individually is a massive disincentive to adding annotations.
I would be nearly impossible for me to accurately assess the flowering phenology based on a single small thumbnail. Whether or not some of the flowers are budding or fruiting would be very easily overlooked.
I’ve personally mostly given up on annotating because of how slow it is, even in Identify mode. If it were possible to do by batch in the uploader only I think that would take care of the “actually take time to look at the thing” concern, since after all they’re my own photos that I was moments ago sorting and cropping.
I just did all of my Eschscholzia poppies in the Identify pane yesterday, and that definitely required opening each one individually and taking a good look for fruits and buds. But it would be easy to distinguish a caterpillar from an adult butterfly from a thumbnail (as was pointed out).