When you place down a single dot of redstone dust, it displays as it would if it was connected on all 4 sides. This has been in the game as long as placeable redstone has been around. This happens on all my versions, iOS and Android.
MCPE-19489
Redstone 4 sided texture
Resolved
Works As Intended
0
(Unassigned)
Unconfirmed
Phone - Android - Motorola Moto G
Android 5.0
1.0.0
Retrieved
Please do not assume that the differences in behaviors between the PC, Pocket Edition, XBOX, PS3, or Raspberry Pi editions of Minecraft are bugs.
Additionally this is a version exclusive feature of the pocket edition