Are they posed similarly?
Are they wearing the same clothing?
Does one person appear taller, shorter, wider, or positioned differently?
This gives you a baseline for comparison.
2. Compare neighboring people
Instead of comparing No. 1 with all six other people, compare No. 1 with No. 2.
Then No. 2 with No. 3.
Continue across the line.
This can make subtle differences easier to see.
3. Examine the face
