Well to be fair, the size of the supermarket seems to have increased substantially. Whether that justifies more than doubling the parking spaces I don't know. It must be said the proposed car park is modest in comparison to the one outside Tesco at the foot of Easter Road.
I also note from the plans that the cycle parking looks pretty decent, and is situated conveniently at the front of the supermarket, with direct access from the street.
You can see the full plans, elevations and visualisations at the Edinburgh planning portal: 15/04194/FUL
Reckon I'll be biking it there when it opens, or walking: depending on the size of the groceries run...
Whether we'll see a lot more traffic on Easter Road is difficult to say. I can imagine LiDL will draw in cars from further east, possibly from the new developments off Albion Road: much of that traffic will try to bypass the traffic light junction at Easter road and doubtless St Clair Street will become even more of a rat run than it already is. That may make the crossroads between St Clair Street, Dalmeny Street and Easter Road more hazardous than it is now. Already this is a junction where cyclists need their wits about them due to impatient drivers trying to cross Easter Road.