As far as I know, any players are not being able to send pictures to KC nor LKC.
I have been playing RoK for nearly 4 years and never seen someone send images to lost kingdom chat until now.
On Facebook, some users flexing their way to sending a picture to Lost Kingdom Chat.
I finally found a way how to send pictures to LKC and KC in RoK, this trick is from a RoK YouTuber, Fleisch on his Community post.
So here is how to do:
Install RoK PC Version (offical app, not emulator ones). Login and open your Rise of Kingdoms account.
Now open Lost Kingdom Chat or KC, and fast tap on (+) icon at bottom left chat, then add images/pictures to send.
You'll need to do this with fast hand, quick to spot the Plus icon.
It might be still a glitch/bug for an unreleased feature, hopefully this means Lilith Games to add this feature officially to Rise of Kingdoms.