Their spelling is not the best, so this cell phone store seems to be a “sell” phone store
Some people make decisions that seem very smart to them, but in the end, everything turns out the other way around. We have a theory about this sign, but the doubts are big ones. We have a sneaking suspicion that these people wrote the word “sell” instead of “cell” on purpose to attract more curious customers with that funny mistake.
But maybe we are overestimating them. The truth is that they made a significant mistake and perhaps aren’t even aware of it. Someone could warn them, so they can change the sign. Maybe they can make a new sign well written, including an illustration related to what they do.