Box 1 is the root box: the window anchored where the scale's root first appears on the low string, with the root under your index finger and — in E minor pentatonic, the worked example — the open strings themselves as the floor. This is the most-recorded hand position in guitar history, and the table below is its complete contents, derived from the scale's intervals rather than copied from a poster.
The window, computed (E minor pentatonic)
| String | Frets | Notes |
|---|---|---|
| 6th string (E) | 0 / 3 | E / G |
| 5th string (A) | 0 / 2 | A / B |
| 4th string (D) | 0 / 2 | D / E |
| 3rd string (G) | 0 / 2 | G / A |
| 2nd string (B) | 0 / 3 | B / D |
| 1st string (E) | 0 / 3 | E / G |
Using it
Practical notes: the root sits on the 6th, 4th, and 1st strings inside this window (the note column above names every pitch, so you can find them), and the two-frets-then-three pattern your fingers feel is just the pentatonic's interval sequence made visible. Phrase inside this box until it bores you, then take the top two strings' notes and find them again at the bottom of box 2 — that overlap is the door out. The full scale, in every key, lives at the scale reference.