The Opportunity tile in Webview has no sorting format you can set or change to edit how they are displayed. The opportunities are supposedly ordered by date added, but I have found instances where that does not hold true.
You can sort the way opportunities/proposals are displayed in database view by lots of different parameters (proposal name, purpose, ask amount, date, etc. but seems like NOT date added).
It would be helpful to sort opportunities alphabetically by name, date added, date of last edit, or ask date in the minimum.