It will just tell us what letters any particular cell likes to connect to, and it will of course tell us the letter of this particular cell (which can also be a blank tile).

It will be called for every grid position in the puzzle to choose a cell that will be a puzzle tile.

If, however, the program is picking the cell for a tile with neighbors "a" and "Q" then the cell affinity for "a" and "Q" will matter.