Picture 1.

Remark

The electron is presented by a fixed line with arrow up for the negative electron and arrow down for the anti  electron (positron).

If the dotted line, which presents the photon, runs up from the vertex, then there is emission.

If the dotted line, which presents the photon, runs down, then there is absorption.

An outgoing anti photon (indicated with a hyphen above the symbol) is equivalent to an outgoing photon, because we cannot distinguish between photon and anti photon.

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