when a redstone repeater is next to an other repeater that's in a 90 degree angle a line goes through it

I put a redstone repeater next another one in a 90 degree angle and a coblestone-looking line went through it as if following the previous repeaters' signal direction

Steps to Reproduce:
1. place a redstone power source (e.g. red. block, torch, etc.)
2. place redstone dust followed by repeater
3. place a repeater next to the last at a 90 degree angle and voila