The PH3 molecule is bent.
This is due to the presence of a lone pair of electrons on the phosphorus atom, which creates a repulsion between the hydrogen atoms and the lone pair. This repulsion pushes the hydrogen atoms closer together, resulting in a bent shape. To visualize this, think of the ideal tetrahedral angle of 109.5 degrees that would be present without the lone pair. However, with the lone pair, the angle between the hydrogen atoms is reduced to less than this ideal angle, confirming the bent geometry.