This is the MCPE counterpart to MC-107934. I would guess that MCPE is the one that is doing it wrong, as repeaters and comparators are placed with their outputs facing away from you, making the MCPE observer placement inconsistent.
MCPE-17321
Observers are placed with the output facing you, unlike the Java edition
Resolved
Works As Intended
2
(Unassigned)
Unconfirmed
Windows
Windows 10 Version 1607
block-placement, observer, redstone
0.15.90.0, 0.15.90.1, 0.15.90.2, 0.15.90.7, 0.15.9, 0.15.10, 0.15.90.8
Retrieved
i remember they say that they change it with how piston is placed (previously similar to a Log placement)