Where Box 1 and Box 2 join
Box 1 and Box 2 share six notes.
This diagram shows Box 1 and Box 2 together. The six ringed notes belong to both positions, spread across six strings. If you move from one position to the other through those notes, the listener hears one continuous line.
Each box of the minor pentatonic is about four frets wide and holds exactly two scale notes on each string. Box 1 starts on the root, box 2 starts on the ♭3, and so on. There are five boxes because the scale has five notes.
Neighbouring boxes are not separate shapes. On every string, the top note of one box is the bottom note of the next. Those six shared notes are called the seams, and they are where you can shift position without breaking the phrase.
Learn box 1 first, then box 2, and then the seam between them. Moving smoothly between two boxes will do more for your playing than learning boxes 3, 4 and 5 as separate shapes.