Which $2$ of these can they do to customize how the accounts appear and make it easy to distinguish between them?

Add the bank name to the account name

Hide Checking $1$ from the Banking center and only display Checking $2$

Customize the background color of one or both of the account tiles

Upload different logo images for one or both accounts

Change the size of the account tiles, making the tile of Checking $1$ bigger

Rearrange the order of the tiles and move Checking $1$ before$$Checking$2$