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I was looking at Murre's notes on the fundamental group of a scheme and came across the following picture, which I find a bit confusing. If someone understands the identification that is supposed to happen, I would be glad to get a clearer description of what is going on.

The full quote includes the following text:

[...] we may take two copies $\tilde C$ and $\tilde C'$ of the normalisation of $C$ and fuse them together is such a way that the points $a,b$ on $\tilde C$ are identified with the points $b',a'$ on $\tilde C'$. We then get a connected but reducible variety $X$ and the morphism $p$ defined in the obvious manner is surely étale.

picture from 3.2

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    A clearer picture of the same construction is given in Figure 12, Exercise III.10.6 on p. 276 of Hartshorne. – 2017-02-01
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    @Nefertiti thank you! – 2017-02-01

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Ok, answering my own question. The user Nefertiti pointed in the comments to the following picture in Hartshorne, and it seems indeed to be a clearer version of the same idea.

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