When perched above the end portal, the dragon will breathe dragon's breath as one of its attacks. In Java Edition, and I think earlier versions of Bedrock Codebase (could someone check this?) there would be dragon's breath particles coming out of the dragon's mouth in a shower-like fashion as the dragon's breath area effect cloud appeared. However, currently no particles come out of the dragon's mouth, and the dragon's breath area effect cloud simply appears.

Steps to reproduce:

1. Go to The End and summon the Ender Dragon if it isn't already there.
2. Switch to survival mode and make sure you don't get killed. (I recommend using /effect @p resistance 99999 250, /gamerule domobspawning false, & /kill @e[type=enderman] to make testing this bug easier.)
3. Wait at the exit portal for the dragon to perch there.
4. When it does, it should try to breathe dragon's breath on you. When it does this, notice that there are no particles coming out of its mouth. Compare to Java Edition.