Perhaps only the 1st year is guaranteed, with a team option for the second year.
Some guarantees are for a partial amount of the player’s salary, and the amount can change on specified dates.
Regardless, on January 10 the base salary in all contracts becomes guaranteed for the remainder of that season.

Dee Brown is a 1-year veteran. As such the minimum salary is $711,517

So here are some scenarios:

Most likely: Washington’s offer is for a two year contract, starting at $711,517 with the first year guaranteed and the team holding an option for the second year. Second year salary probably has an 8% or 10.5% raise.

Next most likely: Washington’s offer is for a two year contract, starting at $711,517 with the first year guaranteed IF he makes the squad out of Training Camp – and the team holding an option for the second year, etc….