 <translate> Working on the masonry of a wall does not mean laying new bricks. It could mean filling in broken mortar or smoothing the mortar now that it has set to get rid of the spikey bits sticking out. It could be getting rid of mold or plants that have dug their way through the mortar and into the brick. I have seen that before.
The final answer: it is not possible to tell. <yor> Ṣíṣe iṣẹ́ lórí ògiri kò túmọ̀ sí gbígbẹ́ bíríkì tuntun. Ó lè túmọ̀ sí pé kí wọ́n fi amọ̀ tí wọ́n ti fọ́ kún un tàbí kí wọ́n rọ amọ̀ náà ní ti pé ó ti fẹ́rẹ̀ẹ́ di èyí tí kò ní àwọn èèpo ẹ̀yìn mọ́. Ó lè jẹ́ pé ńṣe ni wọ́n fẹ́ yọ àwọn nǹkan tó ti bà jẹ́ tàbí àwọn ohun ọ̀gbìn tó ti yọ́ wọnú amọ̀ náà. Mo ti rí irú èyí rí. Ìdáhùn tó ṣe kedere ni pé: kò ṣeé ṣe láti sọ. 