With regard to the pics. I'm not sure why they're rotated but I find that many of the embedded images come up too big to see on screen and won't scroll fully on my phone so I usually read TSP on my laptop and right click then 'view image' which rotates them for viewing the full image.
Now the leotard. I really like the straps but it's what she likes best that counts. The difference in the necklines is partly as you've used a straight top edge for the insert but also because the pink neckline is running straight across at that point too. I can't see the original straight on but it looks as though that's curving down where it meet the mesh. Is it essential to copy it exactly? I only ask as there's nothing wrong with your shape at all.
How did you attach the mesh? Did you cut the pink and then zigzag over the edge? I think can see the stitches just going over very tight to the edge which is quite hard to keep even and although you've managed that here, I think another method may be more foolproof (well I find it easier
). It's less likely that my stitching will go offline as I'm sewing on a smooth flat surface rather than over a cut edge and less likely to hole the more flimsy mesh. I put the mesh under the lycra bodice without cutting away the lycra from the mesh section, stitch around the shape and then cut back the lycra as close as I can to the stitching. I've posted these photos before but I'm not sure if you've seen them. It's the technique that I used on this toile when I was experimenting on drafting a sweetheart neck, later made as a purple latin dress.
Honeycomb stitch along the outline (or 3-step zigzag which lies flatter than normal zigzag
Trim close to the stitching
My DGD insists on sleeves so I've done very few with straps (and they were spaghetti straps or grown on) so I'll leave this to others to comment on the best treatment for attaching them to the neckline edge.