never mind, I finally found a great article explaining with pictures:

http://designforlife.miele.co.uk/uk/en/design/

I've wondered the same thing, and agree it's hard to understand on your own.

What I learned is it depends on the color scheme, in stainless and black, then contour line means one thing, and it depends on whether trim kits (i.e., side panels mounted on each side of say a 24 inch-wide oven mounted in a 30 inch wide cabinet) are used or the appliance itself, no trim kits, is considered.

With colors, Obsidian or Truffle White, etc, I believe contour line is not available.

Below is a link with some good pictures from the Miele US site:

Pages 15-16, 19-20, 21, 23, 27 - Contour
Pages 11-12, 13-14, 16, 18, 28 - Pure

https://www.mieleusa.com/media/ex/us/Brochures%202016/MasterApplianceBrochure_15-1919_G6000_US_3.9.16_FINAL.pdf

Edit to add: The handles on all the appliance doors, ovens, DW, fridge etc., make a difference. Miele has a default handle design for each line, and allows you to override their choice. In effect they pick the best design and allow you to change it. On Miele refrigerators and dishwashers the handle choices are more limited than on ovens, so if you want consistent symmetry lines and finishes then match the handles on ovens and warming drawers with what is available on DWs and refrigerators.

Hope this helps.

As future-retiree said above the all black, white and brown are Pure Line only. Contour line is black and stainless. But I found I got confused as it black/stainless there is contour and pure line. Handle is different. Also on the larger ovens (30 inch) the contour blsck/stainless has stainless on the bottom under the window that pure doesn't. The handle on pure is more low profile (and can be changed to any of he signature handles they sell but that is an extra. I'm not sure if it they can be used on contour line). Contour handle is more ergonomic it pivots allowing your wrist to not have to pivot when you open the door. Miele says pure line is designed for open kitchens more of a blending in look. Functionality of the ovens is identical each has I think has three choices of controls etc (and some other features that vary) put if, for example, you took the top of the line touch screen sensortronic version both pure and contour the ovens work exactly the same.

i really liked the ergonomics of the handle on the countour but I preferred the less stainless look of the 30 inch stainless/black pure line so I'm going pure. Oddly the only plumbed combi steam in pure line is the stainless/black otherwise I might have gone all black.

Looking at the 24" speed oven, the only difference between the two lines is the handle - does one stick out further than the other? I can't tell from the photos, and having a hard time finding dimensions including handle for either.

Agree, finding the depth at which the handles stick out from the front of the oven is not easy. But you can usually find the dimensions, and if not you call Miele tech support.

Here are the drawings and dimensions for one random 24 in oven:

http://www.mieleusa.com/domestic/steam-oven-1466.htm?mat=09682270&name=DG_6500#sketch  See page 5 of 9, and page 9 of 9 which has exact handle dimensions.

I suspected the default handle on the pure line 'sticks out' less than on the contour line (using the default handle choices). That drawing shows this to be the case, a Contour Line handle (Comfort Swivel) is 2-11/16 ins deep, and a Pure Line is 1-5/8 ins deep.

You'll want to find the equivalent drawing for the specific over you're looking at. Go to the specific oven model, then specification downloads then installation drawings. An alternate path, look for Architects & Designers link, then Specification Library.

P.S: Since we're talking handles, have you seen the brochure named Miele Signature Handles, there are some seriously nice looking designs and finishes in there. One of the full context pictures in there shows obsidian black ovens mounted in white cabinets with gold handles. The horizontal gold handles compliment colors and tones in other parts of the rooms. IMO that is a very well done arrangement showing off colors and lines, and showing off a simle use of a higher end finish.

This depicts the dimensions of both the comfort handle and the silhouette handle.