The mathematical identity crisis is real. In the top panel, the elementary charge (1.602 × 10-19 C) is ready to measure electric charge while the derivative operator (d/dx) is confused because it expected Euler's number 'e'. Meanwhile in the bottom panel, Euler's number (2.71828...) shows up for work only to be met with disappointment from Planck's constant 'ħ' who was expecting the elementary charge.
Just another day of constants and operators sharing the same symbols but living completely different mathematical lives. The struggle of notation ambiguity in physics is too real.