Placement guides help you align layers while editing. When you move a layer, guides appear to show the canvas center (horizontal and vertical) and padding boundaries.
When do the placement guides appear?
Photoroom shows the placement guides when:
The feature is on (it is on by default)
When you move a layer across:
The horizontal center line
The vertical center line
Left/right padding edges
Top/bottom padding edges.
The guide colors are:
iOS: pink
Android: pink
Web App: blue.
On the Web App, the placement guides feature is always on. On iOS and Android, it is on by default, but you can turn it off if you prefer, see:

