This Etsy listing has more variation combinations than one Shopify product can hold, so Shuttle did not transfer it. Nothing was created or changed in Shopify.
Why it happens
Shopify allows at most 2,048 variants on one product. Etsy allows up to 2,500 combinations on a listing. So a listing can be fine on Etsy and still be too big for Shopify.
Every combination of option values counts. For example, 50 sizes and 45 colors make 2,250 combinations. To check your listing, open it on Etsy and multiply the number of values in each option.
How to fix it
Decide which combinations your Shopify store does not need. You need to get down to 2,048 or fewer.
Remove those option values from the listing on Etsy. Or, to keep the Etsy listing as it is, leave them out of Shopify only. Go to Settings > Products > Etsy → Shopify > Product Variations and use Exclude variation types or Exclude variations by name. You can also use Exclude variations under Settings > Products > General. If some variations are hidden from buyers on Etsy, you can also turn on Only export visible variations in Product Variations.
Transfer the product again from the Products page.
Automatic transfers skip this listing until it is edited on Etsy. If you only changed your settings, transfer the product yourself.
For more on leaving variations out, see Excluding Specific Variations when Transferring Products to Shopify.
Still seeing it?
If the listing has to keep every option in Shopify as well as on Etsy, it cannot be transferred. Keep it as an Etsy-only listing. If you have brought the listing down to 2,048 combinations or fewer and still see this error, contact support.