Some clematis might work, such as montana or viticella. Not the large flowered type, they are better in the garden. If you do try a clematis then go for the biggest container you can fit there. This only works for a maximum of about 3 years then they start to suffer. You will need to feed and water it well. I had one in a container by my front door and it worked for 3 years.
If you want to “pretty up” walls have you considered wall baskets or hanging baskets? Lots of pretty annuals will grow in pots and can get quite tall. A combination would be very effective
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I cant think of any perennials though.
https://www.taylorsclematis.co.uk/
I would never put a montana in a pot....
I live in west central Scotland - not where that photo is...