Yes! For security a shop can only be connected to one Vela account, but you can connect as many different Etsy and/or Shopify shops to the same account as you like.
To do so simply follow these steps:
Once signed into Vela, click the shop selection dropdown located in the top left hand corner of the app above the sidebar filters.
Click "ADD SHOP" located at the bottom of the dropdown. This will redirect you to the shop selection page.
Select either Etsy or Shopify from which to connect your next shop.
At this point you'll just follow the same steps as when you connected your first shop and once the next shop completes importing into Vela it will appear in the shop selection dropdown. If you have additional shops to connect, just repeat steps 1-3.