Meije Orientale (3,891m)

In the descriptions, you will find elevations which are intended as a reference point to locate your position on a gradient or slope. These should be taken with a margin of error (~ +/- 30 metres), especially where they are not set or referenced by the IGN. In the last resort, it is your own experience that will guide you when, maybe at the foot of five dihedral corners all indistinguishable from one another, you are complaining bitterly about your guidebook or even a friend's sketch. It would be difficult to grasp all the complexity of a route using just a description or a photo view of the route. Only the three aids together (description/photo with a route overlay/IGN map) will give you a comprehensive picture.
The conditions of a route or the mountain can change, and sometimes the description will differ from what you encounter on the ground. Be your own guide. These descriptions are not absolute reality and sometimes intuition will serve you better than a guidebook. So BONNE ROUTE, with or without a map to lead you through the maze!
From the book by Sébastien Constant (2007), Voies normales et classiques des Ecrins, Éditions Constant, L'Argentière-la-Bessée, p. 18.

Standard equipment for snow and mixed itineraries and glacial terrain: telescopic poles, crampons, ice axe, helmet, harness, 50m climbing rope, belaying and progress equipment, 30-litre bag, warm clothing, safety kit etc.