Been using LR with my DD since she was 4.5 months
+ TweedleWink, from 6 month
+ signing time from 12 month.
My DD can flip through the books, play with blocks, do puzzle by herself for long streach of time ....
I think that quality content and short screen time is very essential.
I totally understand "No TV for babies campain" though...
I have a friend who has a daughter 14 month, every time we come, all 4 TVs in her house are on

, both older kids wear glasses,(actually refusing to use glasses...)
I do not think couple minutes a day of LR/ Tweedlewink, etc. will do any harm.