The two Almost Locked Sets (ALSs):
(a)share the Restricted Common Candidate (RCC) X = {2}{0} (b){1}
All X's ({2}'s) in both ALSs see each other (that's the Restriction) so that only one of these two ALSs can contain a {2}, and the other ALS will contain the other common value Z {3}, therefore no cell which sees all {3}'s in both ALSs may be {3}.
The logic is the RCC ({2}) will turn one of the ALSs into a Locked Set (we don't know which yet) and both ALSs also contain digit Z, which is pushed into the other ALS. Meaning that in all ALS cells together one Z must be placed. Hence any cell which sees all the Z's in both ALSs can not be Z.
Therefore
Further explanation
An ALS-XZ is just an ALS-Chain of length 2. An ALS (Almost Locked Set) is
exactly what it sounds like: A Naked Pair/Triple/Quad is a "Locked Set",
and an ALS is "almost locked" because it has just has one more potential
value than its number of cells, so if any value where removed from those
cells it becomes a Locked Set. ALSs are not at all useful until we chain
them together in groups of 2 (ALS-XZ), 3 (ALS-XY-Wing), or more (ALS-Chains).
The 2's and 3's have slightly different rules, so they are handled differently, so we grant them differentiating hint-type names. In ALS-XZ (and ALS-XY-Wings) the RCC (X) is allowed to appear in the physical overlap (if any) of the two sets, in ALS-Chains this is forbidden because it breaks our "and reciprocally" rule. There are also additional eliminations available in double linked ALS-XZs (which this one is not).
{5}