It remains to be seen how Johnson utilizes Stormtroopers in Star Wars: The Last Jedi, and how much – but he sure appears to have an affinity for them.
Ostensibly, Johnson is trying to continue The Force Awakens’ motif of humanizing the Stormtroopers a little more than in previous Star Wars installments.
The photo doesn’t appear to include the rumored “Executioner” Stormtrooper who could do battle with Finn at some point in The Last Jedi.
Stormtroopers have been surprisingly effective before and took on a new, more human dimension in The Force Awakens when Finn had a change of heart and abandoned them.