Alot of the time when breaking or placing blocks a flash of shadow happens. It does not matter what type of pickaxe or enchantments. This happens no matter what. It also doesn't seem to matter you have a light source close by or far away it seems to happen when no light source is placed near by.

Steps to Reproduce:

1. Place or break a block during night or day.
2. placed torches/light source near by
3. removed torches/light sources

Observed Results:
When you place a block there is a flash of shadow, it is very brief, but very noticeable. Could be dangerous for anyone effected by flashing lights. Light source distance doesn't seem to matter. It also happens with torches, lanterns, lava, all light sources i've used so far. It also happens with natural lighting.

Expected Results:
Place blocks without any shadow flashing.

Notes:
I have attached images, If video is needed i'm able to take video of the issue. 1st image is before, 2nd is as it happens, 3rd image is after it is done.

Originally reported for Windows. Also occurs on PlayStation (1.18.2) per MCPE-152066.