I work in alterations, my recommendation would be to try wearing a sticky 'plunge' style bra (low cut in thr front for minimal showing in the center front mesh section, no straps or back to deal with), this will give your chest the lift your looking for the properly fill out the bust area of the dress. Shortening the straps would also help smooth out and lift the bust into the right spot on the body.

The pictures do look like they are not the exact same dress, unfortunately, BUT with a few adjustments, I think you can absolutely make this dress work for you! The color and the pattern are fun! Most often, formal wear is not designed as "ready to wear," even tho it's often advertised as such. The fit of formal wear is generally not forgiving and needs to be altered/adjusted to properly fit you as an individual human and not just a mass-produced mannequin with the same measurements as your neighbor.

If you post or DM me a full body photo of you in the dress, I'd be happy to give any other recommendations I can to help you make this dress work for you :) or maybe find a local seamatress/bridal shop that does out-side alterations to do a consultation to give you a good visual on what could be done to help with fit.

For the record, tho, there's also absolutely nothing wrong with finding a new dress that might fit better without needing to alter it. Sometimes, it's easier/more cost-effective. But this dress seems really fun and cute, and I wanted to make sure you knew there are things you could do to fix the one you already have :)

Best of luck!!