Illusion lace alterations?

Here is a picture of front and back. The straps definitely need to be shortened and the sales people at the store said it wouldn't be an issue but the more I look at it the more have no idea how this could be done?! I'm freaking out!

While I agree with @FallBride, you said that the "sales people" said it wouldn't be a problem. Get that confirmation from a seamstress and you'll be good to go.

I don't always trust sales people when they aren't doing the actual work because they don't know exactly what goes into it.

ETA: And I mean that as a general statement, not something directed at just bridal sales consultants.

Thanks ladies! I def don't trust sales people completely but I'd like to think they wouldn't sell me a dress that was impossible to alter to my body. I'm still having a hard time seeing how alterations won't impact the integrity of the lace appliqués which have big gaps between them on the illusion fabric, but there has to be some way. I have to remind myself I'm not the only person with more narrow shoulders than hips and there are plenty of people who wear illusion lace dresses that also have the same issue. I don't go for alterations until March and it's giving me too much time to think about it!

Also just a thought, Has anyone ever had straps widened? I truly wanted cap sleeves but couldn't find a dress with them that I liked enough. Is it possibly that these straps could be widened with the extra mesh/lace from the hem to make cap sleeves?

I had a concern about my dress as well, so I made a consultation appt with my seamstress just to be reassured. I'm not due for alterations until the beginning of June, but I went last month just so I could stop worrying. Maybe you could do that?

A lot of the time, lace is like an applique, that is sewn onto the shell of the dress, so they can take it off, do the alterations, and sew it back on. Not sure with your dress in particular, but I agree with PPs, if a seamstress says yes, trust them